Answer:
the first and the third one.
Statements that serve as examples of sampling bias are:
A wildlife biologist measuring average deer size only chooses male deer, which tend to be larger than female deer.
A plant ecologist wants to know which insects visit certain flowers,but only samples in the morning around 10:00am.
A marine biologist studies coral reef populations, and samples the same
reef location every day because it has more fish.
A forest ecologist wants to study bird populations so she sets up an
observation station next to the office because it's convenient
Sampling bias can be regarded as a bias whereby a sample is collected, among these samples some members of the intended population will possess lower or higher sampling probability compare to others at the end. Biased sample of a population usually resulted when all individuals, or instances don't have selection.For instance, wildlife biologist that want to measure average deer size, he then choose the male only which is usually larger than the female, his sampling will result to sampling biasTherefore, option the last option is correct.
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If a someone wanted to construct a telescope to observe infrared light in the galaxy who
would best be able to build it
physical engineer
thermal engineer
optical engineer
chemical engineer
Question 13
ipts
Answer:
optical engineer
Explanation:
Answer:optical engineer
Explanation: HOPE IT HELPS YOU .PLEASE GIVE BRAINLIEST THANKS . .
Match each set of quantum numbers to the correct subshell description by typing in the correct number.
1: n = 2, l = 0 2p:
2: n = 3, l = 2 3d:
3: n = 1, l = 0 2s:
4: n = 2, l = 1 4f:
5: n = 4, l = 3 1s:
2p: 4
3d: 2
2s: 1
4f: 5
1s: 3
Explanation: got it all right
Answer:
1: n = 2, l = 0 2p: 4
2: n = 3, l = 2 3d: 2
3: n = 1, l = 0 2s: 1
4: n = 2, l = 1 4f: 5
5: n = 4, l = 3 1s: 3
5. The Santa Ana winds, also known as "devil winds", are strong and dry high-pressure masses of air that begin in the Great Basin mountains and then affect coastal areas in Southern California. Assume that these winds consists of a mixture of nitrogen and oxygen gases that behave ideally and that they begin at a pressure and temperature of 0.705 atm of 22.0 0C, respectively, and that this mass of air is then adiabatically and reversibly compressed to a pressure of 1.00 atm when it descends to the coastal regions. Calculate the final temperature.
Answer:
Explanation:
Given that;
The initial pressure = 0.705 atm
The initial temperature = 22.0° C
The final pressure = 1.00 atm
The objective is to calculate the final temperature,
Since the change occurs adiabatically and reversibly, the final temperature can be calculated by using the thermodynamics equation:
[tex](\dfrac{T_2}{T_1})^r= (\dfrac{P_2}{P_1})^{r-1}[/tex]
where;
r = 7/5 = 1.4
[tex](\dfrac{T_2}{22.0^0})^{1.4}= (\dfrac{1.00}{0.705})^{1.4-1}[/tex]
[tex](\dfrac{T_2}{22.0^0})^{1.4}= (1.418)^{0.4}[/tex]
[tex]T_2 = 22 \times 1.418 ^{^{\frac{0.4}{1.4}}[/tex]
[tex]T_2 = 22 \times 1.418 ^{{0.286}[/tex]
[tex]T_2 =24.31^0 \ C[/tex]
Are sodium and chlorine reactants or products
Answer:
reactants
Explanation:
Although there are the same atoms present in both the reactants and the products, the atoms in the reactants were rearranged to create a new substance, sodium chloride. Sodium chloride was not present in the reactants.
Anyone know about this ?
Answer:
i think its vinegar
Explanation:
Answer:
Vinegar
Explanation:
It is made with several ingredients, including sugar.
Nitric acid is made by a sequence of reactions, shown below. 4NH3(g) +5O2(g) = 4NO(g) + 6H2O(g)
2NO(g) + O2(g) = 2NO2(g)
3NO2(g) + H2O(g) = 2HNO3(g)+ NO(g)
If the first reaction occurs with 96.2% yield, the second reaction occurs with a 91.3% yield and the third reaction proceeds with a 91.4% yield, calculate the following:
(a) The grams of nitric acid produced from 1216 grams of ammonia. (b) The percent yield for the overall process
Answer:
(a) [tex]m_{HNO_3}=2412gHNO_3[/tex]
(b) [tex]Y=80.3\%[/tex]
Explanation:
Hello.
(a) In this case, by starting with 1216 grams of ammonia, we can firstly compute the yielded moles of NO in the first reaction considering the given yield as a fraction (0.962):
[tex]n_{NO}=1216 g NH_3*\frac{1molNH_3}{17gNH_3}*\frac{4molNO}{4molNH_3}*0.962=68.81molNO[/tex]
Next, in the second chemical reaction we compute the yielded moles of NO₂ with the 91.3-percent:
[tex]n_{NO_2}=68.81molNO*\frac{2molNO_2}{2molNO}*0.913=62.82molNO_2[/tex]
Finally, for the percent yield of the last chemical reaction and the molar mass of nitric acid (63 g/mol) we compute the yielded grams of nitric acid:
[tex]m_{HNO_3}=62.82molNO_2*\frac{2molHNO_3}{3molNO_2} *\frac{63gHNO_3}{1molHNO_3}*0.914\\ \\m_{HNO_3}=2412gHNO_3[/tex]
(b) In this case, we compute the moles of NO, NO₂ and the grams of nitric acid as well as the previous literal yet removing the percent yields since we are going to compute theoretical yields:
[tex]n_{NO}=1216 g NH_3*\frac{1molNH_3}{17gNH_3}*\frac{4molNO}{4molNH_3}=71.53molNO[/tex]
[tex]n_{NO_2}=71.53molNO*\frac{2molNO_2}{2molNO}=71.53molNO_2[/tex]
[tex]m_{HNO_3}=71.53molNO_2*\frac{2molHNO_3}{3molNO_2} *\frac{63gHNO_3}{1molHNO_3}*0.914=3004gHNO_3[/tex]
Thus, the overall percent yield is:
[tex]Y=\frac{2412g}{3004g} *100\%\\\\Y=80.3\%[/tex]
Best regards.
5.If the same distance runner started with a blood sodium ion concentration of 142 mmol/L and drank water equivalent to the volume of sweat lost during the race, what is the runner’s ending sodium ion concentration in mmol/L? Average blood volume is 5.00 L. Report your answer to three significant figures. Hint: If the runner drank as much fluid as was lost, what is the runner’s total blood volume at the end of the race? How many moles of sodium ions were in the runner’s blood at the end of the race?
Here is the missing part of the question.
4. A distance runner is in a 4-hour race and sweats at a rate of 455 mL/hour. The sodium ion concentration in sweat is, on average, 920. mg/L. How many moles of sodium ions were lost during the race? Report your answer to three significant figures.
Answer:
Explanation:
Given that:
the time for the runner = 4 hours
the rate of sweating = 455 mL/hour
Therefore, the total sweating rate = 455 mL/hour × 4 hours
the total sweating rate = 1820 mL
The [tex]Na^+[/tex] conc. in sweat = 920 mg/L
Thus, the total number in grams of [tex]Na^+[/tex] sweat lost = [tex]\dfrac{920}{1000}\times 1820[/tex]
= 1674.4 mg
= 1.6744 grams
number of moles of [tex]Na^+[/tex] sweat lost = mass of [tex]Na^+[/tex] sweat lost/ molar mass of [tex]Na^+[/tex]
number of moles of [tex]Na^+[/tex] sweat lost = 1.6744/ 23
number of moles of [tex]Na^+[/tex] sweat lost = 0.0728 mole
5. concentration of the runner = 142 mmol/L
the average volume of blood = 5.00 L
the number of moles sodium [tex]Na^+[/tex] = concentration × volume
the number of moles sodium [tex]Na^+[/tex] = 142 mmol/L × 5.000 L
the number of moles sodium [tex]Na^+[/tex] = 710 mmol
the number of moles sodium [tex]Na^+[/tex] = 0.710 mol
recall that; the number of moles of [tex]Na^+[/tex] sweat lost = 0.0728 mol
thus, the number of remaining [tex]Na^+[/tex] = (0.71 - 0.0728) mol
the number of remaining [tex]Na^+[/tex] = 0.6372 mol
The runner ending [tex]Na^+[/tex] concentration = 0.6372 mol/ 5.00 L
The runner ending [tex]Na^+[/tex] concentration = 127440 mmol/L
What is a chemical that organisms use for primarily energy
A-protein
B-carbohydrate
C-lipid
D- water
Undigested food leaves the body through the...
A small intestine
B rectum
C Oliver
D pancreas
Answer:
That is B. RectumExplanation:
The answer is the rectum because the small intestine takes the nutrients and delivers toxins to the kidneys, and the pancreas is an organ that helps digest hormones that help regulate the way your body processes sugar.
Answer:
B
Explanation:
Rectum.
It's definitly right. I had this on a quiz.
Which of the is an example of climate???
Help pls?
A student performed an investigation at sea level. First she placed 400 mL of water in four different containers. Then she placed the containers on hot plates with four different temperature settings, as shown in the table.
Answer:
C. The boiling point of water
Explanation:
We assume your question is the one attached.
Obviously, the shape of the (liquid) water is a function of the container it is in, as it is for any liquid or gas.
The rate of evaporation will depend on the temperature and on the surface area. The different containers are different in both ways, so evaporation is not a constant.
The boiling point is a physical property of the water, so will be the same across all containers.
The amount of steam released is related to the rate of evaporation. It will not be a constant across the different containers.
__
The appropriate choice is ...
The boiling point of water
Which of the following ideas helps explain the factors that affect island colonization of and species richness for a region?
I. Species-area effect
II. Rescue effect
III. Target effect
IV. Time/stability hypothesis I and II
Il and III
I, II, IV
I, II, III, IV
Answer:
Its I, II, III, IV
Explanation:
I took the test
I, II, III, and IV factors that affect island colonization and species richness for a region. Hence, option D is correct.
What is colonization?Colonialism is defined as “control by one power over a dependent area or people.”
Immigration to an island is affected by the distance of the island from a source of colonists. Usually, this source is the mainland (and it will be for this lesson), but it can also be other islands. Islands that are more isolated are less likely to receive immigrants than islands that are less isolated.
Hence, the species-area effect, rescue effect, target effect and time/stability hypothesis affect island colonization and species richness for a region.
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Astatine belongs to which element group: nonmetal, halogen, noble gas?
Answer:
halogen
Explanation:
It belongs to Group 17 on the periodic table, which is a halogen
Astatine is a periodic element that is represented as At and has the atomic number of 85. This element belongs to the halogen group of the periodic table. Thus, option b is correct.
What are halogens?Halogens are the group or the families of the periodic table that are characterized by the six elements that are non-metallic in nature. The other halogens are iodine, chlorine, bromine, fluorine, and tennessine.
The astatine element of the halogen group (group 17) is the rarest naturally occurring and have an electronic configuration of [Xe] 4f¹⁴5d¹⁰6s²6p⁵, with atomic number 85.
The isotopes of astatine are not stable and are used to treat a disease like a thyroid in radiotherapy. Also, it is used to treat cancerous cells.
Therefore, option b. the astatine element is a halogen.
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Stereoisomers that are not mirror images of each are ____________ . The chemical and physical properties of two ____________ are different. Isomers that differ only in the way atoms are oriented in space are ____________ . Achiral compounds that contain tetrahedral stereogenic centers are ____________ . Isomers that differ in the way the atoms are connected to each other are ____________ . Stereoisomers that are nonsuperimposable mirror images of each other are ____________ . The chemical and physical properties of two ____________ are identical except in their interaction with chiral substances.
Answer:
Stereoisomers that are not mirror images of each are diasteroisomer . The chemical and physical properties of two diasteroisomers are different. Isomers that differ only in the way atoms are oriented in space are Stereoisomers . Achiral compounds that contain tetrahedral stereogenic centers are meso isomers . Isomers that differ in the way the atoms are connected to each other are structural isomer . Stereoisomers that are nonsuperimposable mirror images of each other are enantiomers . The chemical and physical properties of two enantiomers are identical except in their interaction with chiral substances.
Explanation:
Diasteroisomers are differentiated by the spatial arrangement of atoms, but they are not specular images so they are not enantiomers. In order for two molecules to be diastereoisomers, they must have at least two chiral centers. In one of the centers the substituents are arranged equally in both molecules and in the other they must change.
Enantiomers are specular images but are not superimposable. They have the ability to rotate the polarized light plane
The stereoisomers present the same molecular formula but different spatial rearrangement between their atoms, we can mention the cis and trans isomers where the cis isomers are on the same side of the plane and the trans isomers on opposite sides. They are also known as geometric isomers.
Meso compounds always have more than one asymmetric center and are aquiral. They are distinguished because they present a plane of symmetry.
Structural isomers are those that have different connectivity between their atoms. We can differentiate, for example, metoximethane from ethanol. They will always have the same molecular formula.
is burning of maganisums exothermic or endothermic reaction
Answer:
Exothermic I think
Explanation:
If you have a glass capillary tube that is 0.275 mm in radius, and you push it into water then the water will rise, but if you push the capillary into mercury in will create a meniscus below the surface of the fluid. If air is the gas phase, then the surface tension of water at 140oF is 66.2 mN/m and the surface tension of mercury is 470 mN/m. If the contact angle of water on glass is 10oand mercury on glass is 130o, then calculate BOTH height changes.
Answer:
Explanation:
From the given information, the rise in a capillary tube h = [tex]\dfrac{2T cos \theta }{r \rho g}[/tex]
where:
For the height of water:
Surface Tension T = 66.2 mN/m = 66.2 N/m
θ = 10⁰
Cos θ = cos 10 = 0.985
radius r = 0,257 mm = 0.275 × 10⁻³ m
density of water [tex]\rho[/tex] = 1000 kg/m³
g = 9.8 m/s²
∴
replacing our values:
h = [tex]\dfrac{2T cos \theta }{r \rho g}[/tex]
h = [tex]\dfrac{2\times 66.2 \times 10^{-3} \times 0.985}{0.275 \times 10^{-3} \times 1000\times 9.8}[/tex]
h = 0.0484 meteres
h = 48.3 mm
Since the height h = [tex]\dfrac{2T cos \theta }{r \rho g}[/tex]
r = 0.275 mm = 0.275 × 10⁻³ m
the density of mecury now [tex]\rho_H{g}}[/tex]
= 13593 kg/m³
the surface tension of the mercury [tex]T_{Hg} =470 \times 10^{-3} \ N/m[/tex]
θ = 130⁰
Cos θ = cos 130 = -0.6428
Using the same above equation:
h = [tex]\dfrac{2\times 470 \times 10^{-3} \times (-0.6428) }{0.275 \times 10^{-3} \times 13593 \times 9.8}[/tex]
h = -0.016494 m
h = 16.49 mm
When writing equations the mass on the left of the arrow must
equal the mass on the right of the arrow.
Answer:
When writing equation the mass on left side of equation must be equal to the mass on right side. True
Explanation:
The chemical reactions always follow the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
Explanation:
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass because total mass is equal on both side of equation.
How many cm is equal to 1450 nm?
a
1.45 x 10-8.cm
b 1.45 x 1010 cm
С
1.45 x 1014 cm
d
1.45 x 10-4 cm
Answer:
The answer is D; 1.45 x 10^-4
Where can you find the number of electrons of an
element?
Answer:
Subtract the charge from the atomic number. When an ion has a positive charge, the atom has lost electrons. To calculate the remaining number of electrons, you subtract the amount of extra charge from the atomic number. In the case of a positive ion, there are more protons than electrons.
Explanation:
Answer:
Explanation:
electrons is same as the amount of protons. and protons are also same as the atomic #.
WILL GIVE YOU Brainliest!!!!!!
2. Calculate the volume for the following object If you know that the object has a mass of 24 grams and the density is 12 g/ml.
Answer:
2 ml=2 cm³
Explanation:
volume=mass/density
1ml= 1cm³
= 24g/12g/cm³
= 2 cm³
Answer:
2 ml=2 cm³
Explanation:
volume=mass/density
1ml= 1cm³
= 24g/12g/cm³ = 2 cm³
please mark me brainiest you said you would!
100 POINTS & BRAINLIEST !!!! PLEASE HELP
Answer:
The more you get closer to a substance in the periodic table things that are included into the substance start to get bigger
Explanation:
Which element is a non reactive gas?
Lead (82)
Argon (18)
Gold (79)
What is the mass of 3.15 moles of calcium sulfate, CaSO4?
Answer:
3.15 * 136 (136 is the molar mass of calcium sulfate). = 428 g CaSO4.
Explanation:
An object in motion has Energy
A: magnetic
B: kinetic
C: possible
D : chemical
Draw the structure of the product that is formed when the compound shown below undergoes a reaction with PhMgBr and then is treated with water.
Answer:
please find the attached file.
Explanation:
A second calibration standard solution of an iron(III) salicylate complex was prepared in two steps. First, 30.8 mL of a 0.185 M stock solution was diluted with solvent to make 100.0 mL of the first calibration standard solution and, secondly, 78.5 mL of that first calibration solution was diluted to 100 mL to make the second calibration standard. What is the molar concentration of the second calibration standard solution
Answer:
0.0447 M.
Explanation:
We'll begin by calculating the molarity of the diluted solution of the first calibration standard solution. This can be obtained as follow:
Molarity of stock solution (M1) = 0.185 M
Volume of stock solution (V1) = 30.8 mL
Volume of diluted solution (V2) = 100 mL
Molarity of diluted solution (M2) =?
M1V1 = M2V2
0.185 × 30.8 = M2 × 100
5.698 = M2 × 100
Divide both side by 100
M2 = 5.698 / 100
M2 = 0.05698 M
Therefore, the molarity of the diluted solution of the first calibration standard solution is 0.05698 M
Finally, we shall determine the molarity of the second calibration standard solution as follow:
Molarity of first calibration standard solution (M1) = 0.05698 M
Volume of first calibration standard solution (V1) = 78.5 mL
Volume of second calibration standard solution (V1) = 100 mL
Molarity of second calibration standard solution (M2) =?
M1V1 = M2V2
0.05698 × 78.5 = M2 × 100
4.47293 = M2 × 100
Divide both side by 100
M2 = 4.47293 / 100
M2 = 0.0447 M
Therefore, the molarity of the second calibration standard solution is 0.0447 M.
Which of the following answer choices represents a typical anion
Answer:
This question is incomplete
Explanation:
This question is incomplete but generally, anions are ions that are made up of an atom or group of atoms (polyatomic) that are negatively charged. The first thing one should look out for when trying to identify an anion is the negative charge. Examples of anions include Cl⁻, O²⁻, N³⁻, NO₃⁻, SO₄²⁻, PO₄³⁻and AsO₄³⁻.
You weighed your empty insulated cup and found that the mass of the cup was 3.2 g. You add some hot water and find that the total mass increases to 28.1 g. You got some ice from the bus tub, and found that it was wet. After drying it carefully, you take the temperature of the hot water in the cup and find that its temperature is 60.7 °C and then add the ice. The temperature of the water dropped, and came to equilibrium at 35.1 °C. At the end of the experiment you re-weigh the cup and find that the mass has increased to 33.0 g.What was the initial temperature of the ice?What is your experimental value for the heat of fusion?
Answer:
Initial temperature of ice for this experiment = 0⁰c
heat of fusion = 95 cal
Explanation:
mass of empty cup = 3.2 g
mass of cup filled with hot water = 28.1 g
hence : mass of hot water = 28.1 - 3.2 = 24.9 g
mass of hot water + ice + empty cup = 33.0 g
hence : mass of ice = 33.0 - 24.9 - 3.2 = 4.9 g
temperature of hot water = 60.7⁰c
when ice was added ( temperature of mixture ) = 35.1⁰c
A) Initial temperature of the ice
initial temperature of ice is 0⁰c
B) experimental value for heat of fusion
we have the apply the law of energy conservation
= heat lost(hot water ) = heat gain by ice s = specific heat of water = 1 cal
= M*s*ΔT = Mice * Hf + Mice *s *T
= 24.9 * 1 * ( 60.7 - 35.1 ) = 4.9 * Hf + 4.9 * 1 * 35.1
= 24.9 ( 25.6 ) = 4.9 hf + 171.99
Hf ( heat of fusion ) = 465.45 / 4.9 = 94.99 ≈ 95 cal
The Initial temperature of ice for this experiment is 0⁰c
The experimental heat of fusion of ice is 95.1 cal/g
Temperature of wet iceWet ice means ice with water on top of it or ice that is melting.
Since the ice was wet or melting, it means that its temperature was 0⁰c
Initial temperature of ice for this experiment = 0⁰c
Experimental value of the heat of fusion of ice.Heat of fusion is the amount of heat energy required to melt a given amount of a solid at its melting point.Using the law of conservation of heat
Heat lost by hot water = Heat gained by iceinitial temperature of ice is 0⁰c
mass of empty cup, m1 = 3.2 g
mass of cup filled with hot water, m2 = 28.1 g
mass of hot water, m3 = m2 - m1
mass of hot water = 28.1 - 3.2
mass of hot water = 24.9 g
mass of hot water + ice + empty cup, m4 = 33.0 g
mass of ice, m5 = m4 - m2
mass of ice = 33.0 - 28.1 = 4.9 g
temperature of hot water = 60.7⁰c
final temperature of ice + hot water mixture = 35.1⁰c
Initial temperature of the ice = y
Heat lost by hot water, H = mcΔT
where m = mass of hot water
c = specific heat of water = 1 cal
ΔT = temperature change
H = 24.9 × 1 × {35.1 - 60.7}
H = 637.44
Therefore, Heat gained by ice = 637.44
Heat gained by ice = Heat gained in changing from ice at 0°C to water at 0°C + Heat gained in changing from water at 0°C to water at 35.1°CHeat gained in changing from ice at 0°C to water at 0°C = m×Hf
where m is mass of iceHf is heat of fusion of iceHeat gained in changing from water at 0°C to water at 35.1°C = mcΔT
where m = mass of water at 0°C
c = specific heat of water = 1 cal
ΔT = temperature change
Heat gained by ice = 4.9 × Hf + 4.9 × 1 × {35 - 0}
Heat gained by ice = 4.9 × Hf + 171.5
637.44 - 171.5 = 4.9 × Hf
Hf = 465.94/4.9
Hf = 95.1 cal/g
Therefore, Heat of fusion of ice = 95.1 cal/g
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Which electrons determine the reactivity of the atom?
Questions
Vacuoles are round organelles found in both plant and animal cells. Their primary function is to -
produce food and energy for the cell.
control the activities of the cell.
transport materials between parts of the cell.
O
store water, waste, and nutrients for the cell.
Answer:
store water, waste, and nutrients for the cell
