Which of these two statements meets the criteria of a
scientific hypothesis?
a. Acids turn red litmus paper blue.
b. All life in the universe exists on Earth.
Litmus paper can't accurately determine how acidic or alkaline a substance is because the results are qualitative (observable), not quantitative (measurable).
What is Litmus paper?
Mechanism. It contains a mild acid, red litmus. The hydrogen ions interact with the additional base when it is in contact with a basic substance.
The moist red litmus paper turns blue when placed in an alkaline solution because the conjugate base that is created from the litmus acid has a blue.
Chemistry uses a litmus or litmus paper test to detect if a solution is basic or acidic. Some lichen species are the source of litmus.
When exposed to an acid, litmus will turn red; when exposed to a base, it will turn blue.
Therefore, statements a meets the criteria of a scientific hypothesis.
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A student has an unknown sample. How can spectroscopy be used to identify the sample?
It can identify the elements in the sample.
It can determine the number of electrons in the sample.
It can determine the ratio of the elements in the sample.
It can determine the molecular structure of atoms in the sample.
Answer: A. It can identify the elements in the sample.
Explanation: on edge
Spectroscopy is the technique used in analytical chemistry. An unknown sample can be identified by spectroscopy as it can determine the elements. Thus, option A is correct.
What is spectroscopy?Spectroscopy is an analytical technique that can determine the atomic and molecular structure of the sample by the method of absorption and emission of the energy by the particles of the matter.
The particles or the atomic elements absorb the electromagnetic radiation from the source and emit a specific spectrum or wavelength that is a characteristic of an element.
This spectrum allows the deduction of the structural details and the electronic configuration that is used to know the element or the atom present in an unknown sample.
Therefore, option A. spectroscopy can identify the elements in the unknown sample.
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describe the difference between corrosion and rust
The main difference between corrosion and rust is that corrosion occurs as a result of the chemical influence and it affects a lot of materials whereas rusting is only accelerated by certain chemicals and usually affects iron substances
Hopes this helps :)
156 g sample of steel has a volume of 20.0mL What is the density of the steel sample?
__g/cm^3
Your answer should round to three significant figures.
Answer:
The answer is
7.80 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 156 g
1 mL = 1 cm³
20 mL = 20 cm³
volume = 20 cn³
The density of the metal is
[tex]density = \frac{156}{20} = \frac{39}{5} \\ [/tex]
We have the final answer as
7.80 g/cm³ to 3 significant figuresHope this helps you
Which scientist developed the 1st model of the atom that showed the structure of the inside of an atom?
A. Dalton
B. Borh
C. Rutherford
D. Thomson
Describe the relationship between atoms and molecules
Answer:
Atoms are the smallest particle that an element can be divided in to. When atoms come together, they form molecules and molecules start to create everything around you.
Atoms are the smallest particles of matter which on combining with atoms of the same type give rise to molecules.
What is matter?
Matter is a substance which is made up of various types of particles which occupy space and have inertia . All living things and objects are made up of various types of particles that occupy space and have inertia .
Depending on temperature and other factors matter is able to exist in different phases. Most common of which are solid, liquid and gas. Matter can exist in more than one state depending on the temperature and pressure .
State of matter can be changed by heating or cooling and even by changing the applied pressure.When a state changes matter does not break rather its state changes though its chemical composition remains same.
Physical characteristics of matter are shape, color, size and temperature. Every matter is made up of elements which cannot be broken down further by ordinary chemical reactions.
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I need help I have a time limit please helpppp
Answer:
Is it D?
Explanation:
I need help with the 14 and the 15
Answer:
I could not see the photo please resend the photo
A sample of Element X is found to contain 67.25% of isotope type 1 (85.91) and 32.75% of isotope type 2 (87.91). Calculate the average atomic mass.
Answer:
The average atomic mass is 86.565
Explanation:
An element's average atomic mass is the sum of the products of the masses of the isotopes of the element and their percentage abundance divided by 100
The average atomic mass of the Element X is given as follows;
Isotope type 1 (85.91) ×
Isotope [tex]{}[/tex] Abundance (%) Mass /100 Portion of average mass
Type 1 [tex]{}[/tex] 67.25 × 85.91 ÷ 100 57.774475
Type 2 [tex]{}[/tex] 32.75 × 87.91 ÷ 100 28.790525
[tex]{}[/tex] Average atomic mass = 86.565
The average atomic mass = 86.565.
Andy is waiting at the signal. As soon as the light turns green, he accelerates his car at a uniform rate of 8.00 meters/second2. What is the displacement of Andy’s car after 30.0 seconds?
A.
1200 meters
B.
2400 meters
C.
3600 meters
D.
4800 meters
E.
7200 meters
Sodium carbonate solution reacts with dilute hydrochloric acid. The equation for the reaction is shown.
Na2CO3(aq) + 2HCl(aq) → 2NaCl(aq) + CO2(g) + H2O(l)
Excess sodium carbonate is added to 10.0cm3 of 0.10mol/ dm3 hydrochloric acid.
Which volume of carbon dioxide gas is made?
A 12cm3 B 24cm3 C 12000cm3 D 24000cm3
Answer:
12000cm³ is the answer
hope it helps you mate please mark me as brainliast
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, volume of carbon dioxide gas made is 11.2L.
What is mole?The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
The balanced equation for the given reaction can be given as
Na[tex]_2[/tex]CO[tex]_3[/tex](aq) + 2HCl(aq) → 2NaCl(aq) + CO[tex]_2[/tex](g) + H2O(l)
moles of hydrochloric acid = 10.0dm³ × 0.10mol/ dm³
=1 mole
The mole ratio between carbon dioxide and HCl is 1:2.
mole of CO[tex]_2[/tex]=0.5 moles
volume of CO[tex]_2[/tex]=moles× 22.4
=0.5 ×22.4
=11.2L
Therefore, volume of carbon dioxide gas made is 11.2L.
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Which is the best step for Peta to take next? During a science lab, Peta poured two clear chemicals into different beakers. Afterward, he realized that he did not label the beakers so he could not tell the chemicals apart. smell them in order to identify them O taste them in order to identify them O mix them together and pour them down the drain O ask the teacher to dispose of them and start over
Answer:
d
Explanation:
because i took the test
Answer:
D
Explanation: took test and it was right
Consider a situation in which the enzyme is operating at optimum temperature and pH, and has been saturated with substrate. What is your best option for increasing the rate of the reaction?HintsIncrease the pH.Increase the temperature.Increase the enzyme concentration.Increase the substrate concentration.
Answer:Increase the enzyme concentration
Explanation:
If the enzyme is saturated, it simply means that all the enzyme molecules present has been bound to substrates.
Of course, there will still be more substrates left in the system since the enzyme is saturated. The reaction rate can now be increased by increasing the enzyme concentration so that more enzyme molecules can be bound to substrates.
a student investigated and recorded how the amount of study time affected the scores on a science test
Sodium and chloride ions readily combine because they have opposite charges.
O True
O False
HURRY!!!
Answer:
its true i just looked on quizlet
Explanation:
An organ like the brain is considered to be a living thing, how is it possible?
Answer: The brain is an organ, and a very unusual and complex one at that. It plays a role in every one of our functions, controlling many organs, our thoughts, memory, speech, and movements.
Explanation:
According to the law of conservation of matter, what cannot change during a chemical reaction?.
OA. the number of atoms
ОВ.
the color of substances
OC.
the state of matter
OD. the temperature
What cannot we change during a chemical reaction
Answer:
the number of atoms
Explanation:
atoms are never created not destroyed
Please help me! I will give a 7 point Brainliest and 13 points!
What is the molarity of a solution prepared from 19.4 g NaCl in 300.0 mL of solution?
Answer:
1.11 M NaCl
Explanation:
Quizlet???
Explain how you would separate a mixture of sand and water.
Answer: When sand is added to water it either hangs in the water or forms a layer at the bottom of the container. Sand therefore does not dissolve in water and is insoluble. It is easy to separate sand and water by filtering the mixture. Salt can be separated from a solution through evaporation.
Explanation:
0
10
20
30
40
50
60
70
80
90
100g
100
200
300
400
500g
0
1
2
3
4
5
6
7
9
10g
mass =
Answer:
2047
Explanation:
After throwing the ball in the pool for my dog the ball sprung a leak and begin to fill with water. How many mL of water can the ball absorb before the ball sinks
Answer: i think 250ML
Explanation:
Hi! i’m not sure which one this is, please help. (:
Answer:
Explanation:
-"If he wanted to keep 'em after he was dead, a wicked old screw," pursued the woman, "why wasn’t he natural in his lifetime? If he had been, he'd have had somebody to look after him when he was struck with Death, instead of lying gasping out his last there, alone by himself."
This is showing that if he hadn't be so selfish and righteous, then he would not have been alone to die without anyone there to help or comfort him. In the line, "why wasn't he natural in his life?", is asking why he wasn't a nice person. Why didn't he help others. If he had helped others, he would not have been so alone.A story set during a major battle, as both have a sudden rush of events.
Is a pH of 7 high pH or neutral??
Answer:
neutral
Explanation:
pH range goes from 0-14, since 7 is in between 0 and 14, it is neutral.
What is the energy of a wave with wavelength of 4.2 x 10-7 m. (Hint: Calculate for frequency first.)
A. 4.74 x 10-28 Joules
B. 4.74 x 10-19 Joules
C. 8.35 x 10-32 Joules
D. 2.79 x 10-40 Joules
Answer:
Option B. 4.74×10¯¹⁹ J.
Explanation:
The following data were obtained from the question:
Wavelength (λ) = 4.2×10¯⁷ m
Energy (E) =.?
Next, we shall determine the frequency of the wave. This can be obtained as follow:
Wavelength (λ) = 4.2×10¯⁷ m
Velocity (v) = constant = 3×10⁸ m/s
Frequency (f) =.?
v = λf
3×10⁸ = 4.2×10¯⁷ × f
Divide both side by 4.2×10¯⁷
f = 3×10⁸ / 4.2×10¯⁷
f = 7.143×10¹⁴ s¯¹
Therefore, the frequency of the wave is 7.143×10¹⁴ s¯¹.
Finally, we shall determine the energy of the wave using the following formula
E = hf
Where
E is the energy.
h is the Planck's constant
f is the frequency
Thus, the enery of the wave can be obtained as follow:
Frequency (f) = 7.143×10¹⁴ s¯¹.
Planck's constant = 6.63×10¯³⁴ Js
Energy (E) =..?
E = hf
E = 6.63×10¯³⁴ × 7.14×10¹⁴
E = 4.74×10¯¹⁹ J
Therefore, the energy of the wave is 4.74×10¯¹⁹ J.
in periodic table, valance electrons are indicated by
distinguish among a mixture, a solution, and a compound.
Use the drop-down menus to complete the statements.
Each organism in a population produces more offspring than can survive. This is called
.
In order for natural selection to occur, populations must have
.
When the environment changes, nature selects favorable
. Over time, these
in a population.
Answer:
(1) 3
(2) 2
(3) 1
(4) 2
Explanation:
Use the drop-down menus to complete the statements.
Each organism in a population produces more offspring than can survive. This is called
✔ overproduction
.
In order for natural selection to occur, populations must have
✔ variation
.
When the environment changes, nature selects favorable
✔ adaptations
. Over time, these
✔ build up
in a population.
1. The reproduction of more offspring than can survive by each organism in a population is called overproduction.
2. The various populations in an ecosystem must have variation, in order for natural selection to occur.
3. When the physical environment in an ecosystem changes, nature selects favorable adaptations.
4. Over time, these favorable adaptations build up in the population of living organism.
Natural selection can be defined as a biological process in which the species of living organisms possess certain traits, characteristics, and qualities that enables them to successfully adapt to various environmental factors, survive and reproduce, as well as passing on genes to subsequent generation. Some of the environmental factors that affects natural selection include the following;
Competition for foodClimate changePredatorsSex matesBased on evolution, living organisms that are best suited for the new environment would survive and reproduce when there is a change in the physical environment.
Consequently, nature selects favorable adaptations and they are passed on to the next generation (offspring). Over time, these favorable adaptations build up in the population of living organism, and then the population would evolve.
In conclusion, natural selection entails the survival of the fittest organism within an ecosystem.
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An area of the atom that holds negative particles
Atoms consist of three basic particles: protons, electrons, and neutrons. The nucleus (center) of the atom contains the protons (positively charged) and the neutrons (no charge). The outermost regions of the atom are called electron shells and contain the electrons (negatively charged).
What color is a mirror?
Answer:
mirrors do not have a color, many people believe they are green because they reflect the most green light back into our eyes.
8. Your pigs are going through ten 50.0 lb bags of feed per week. How many kilograms of feed are the pigs
eating per day?
HELP ME PLEASE
Answer:
8. 3.24 kg
9. 6.31 litres/minute.
10a. 15.3 m³
10b. $ 612.
Explanation:
8. Determination of the kilogram of feed eaten by the pig per day.
From the question given,
The pig consumed = 50 lb bags
Duration = 1 week
Consumption per day =..?
Next, we shall convert 50 lb to kg. This can be obtained as follow:
1 lb = 0.454 Kg
Therefore,
50 lb = 50 lb × 0.454 Kg/ 1 lb
50 lb = 22.7 kg
Next, 1 week us equivalent to 7 days.
Thus, the pigs consumed 22.7 kg of feed in 7 days. Therefore, the pigs will consume X kg of feed in 1 day i.e
X kg of feed = 22.7/7
X kg of feed = 3.24 kg
Therefore, the pigs will consume 3.24 kg of feed per day.
9. Determination of the rate in litres/minute.
Rate = 100 gallon/hour
Rate (litres/minute) =?
We'll begin by converting 100 gallon/hour to litre/hour. This can be obtained as follow:
1 gallon/hour = 3.785 litres/hour
Therefore
100 gallon/hour = 100 × 3.785
100 gallon/hour = 378.5 litres/hour
Finally, we shall convert 378.5 litres/hour to litres/minute. This can be obtained as follow:
1 litre/hour = 1/60 litre/minute
Therefore
378.5 litres/hour = 378.5 × 1/60
378.5 litres/hour = 6.31 litres/minute.
Therefore, 100 gallon/hour is equivalent to 6.31 litres/minute.
10a. Determination of the concrete in m³.
Concrete needed = 20 yd³
Concrete needed (in m³) =...?
1 yd³ = 0.765 m³
Therefore,
20 yd³ = 20 yd³ × 0.765 m³/ 1 yd³
20 yd³ = 15.3 m³
Therefore, 20 yd³ is equivalent to 15.3 m³
10b. Determination of the cost spent on the wall. This can be obtained as follow:
1 m³ = $ 40
Therefore,
15.3 m³ = 15.3 m³ × $ 40 / 1 m³
15.3 m³ = $ 612
Therefore, $ 612 will be spent on the wall.
