PLZ
how many molecules are in 2so4​

Answer:

_ NH4NO3 -> _ N2O + 2 H2O

Explanation:

By having 2 water molecules, we reach the 4 H atoms and 3 O atoms that are present on the left side. We don't add any other coefficients because we already have enough N atoms and we don't have to manipulate the left side at all.

Answer:

protons 19

nuetorns 20

electrons 19

metling point 63.65 C

Explanation:

Answer:

Answers with detail given below.

Explanation:

Ionization trend along period:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases.

Ionization trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

As the size of atom increases the ionization energy from top to bottom also  decreases.

Elements with lower ionization energy:

11) B

12) Ga

13) K

14) P

15) Cr

Answer:

120.37 g/mol is the molar mass of magnesium sulfate

Answer:

348.9 mL of the 60% solution and 251.1 mL of the 15% solution.

Explanation:

First, we calculate how many mililiters of pure carbonic acid are there in 650 mL of a 38% solution:

Then we can express the sum of both initial solutions as:

for the volume of carbonic acid; and

For the volume of the solutions.

We now have a system of two equations and two unknowns (x is the volume of the 60% solution and y is the volume of the 15% solution).

We express x in terms of y in equation 2):

And replace x in equation 1):

Finally we calculate x using equation 2):

Answer:

Freezing the mix is one of the most important operations in making ice cream, for upon it depend the quality, palatability, and yield of the finished product. Typically, freezing of ice cream is accomplished in two steps: (1) dynamic freezing, where the mix is frozen quickly while being agitated to incorporate air and to limit the size of ice crystals formed; and (2) static freezing, where the partially frozen product is hardened without agitation in a special low-temperature environment designed to remove heat rapidly. Although these steps primarily encompass freezing, or the formation of ice crystals, there are several other important processes that take place during this time that significantly impact the quality of ice cream. Both the dispersion of air bubbles and rearrangement of fat globules occur during the freezing steps.

Explanation:

true  becouse i sed so                                            

Answer:

turtles

Explanation:

Turtles eat frogs and no animal in the pond can consume a turtle

Answer:

. A(n) _______________________________ is matter that is composed of 2 or more different kinds of atoms.

2. A chemical reaction in which energy is released/given off is _____________________________________.

3. A(n) _________________________________ is a process in which substances are changed into other

substances.

4. Matter that is composed of only 1 kind of atom is a(n) ______________________________.

5. ___________________ is the ability to do work and/or transfer heat.

6. A chemical reaction in which energy is absorbed/taken in is _______________________________.

Knew/New

Write down 3 things you already knew about chemical reactions that were confirmed through watching the

video:

1.

2.

3.

Write down 3 new things that you learned from watching the video:

1.

2.

3.

Episode Guide

1. Chemicals can react to form new _________________________________.

2. Chemical reactions happen when ____________________ hook together.

3. Energy is given off during a chemical reaction because ____________________ are combining with other

__________________________.

4. During the "Try this" experiment, we see the students using vinegar and salt to clean old copper pennies.

The copper gets stripped away and the pennies look new again. Explain why you think this happens.

__________________________________________________________________________________________

Answer Key

compound

exothermic

chemical reaction

element

Energy

endothermic

Answers will vary.

Answers will vary.

chemicals

electrons

electrons

electrons

Copper atoms in the penny react with oxygen atoms from the air & together they form copper oxide which

makes the pennies look dull and dirty. The copper oxide dissolves in a weak acid (the vinegar & salt).

5. When vinegar and baking soda react together, the new substance that is produced is ___________________.

6. _______________ & ______________ are both dangerous by themselves, but when they react together they

form table salt.

7. Pyrotechnician is a name given to people who work to create _________________________.

8. In another experiment, we see kids blow up a balloon by mixing together vinegar and baking soda. When

the kids touch the blown up balloon, it is ____________ to the touch. This means that the reaction is

endothermic or exothermic

9. When someone gets hurt playing sports, often times a cold pack is used for the injury. The cold pack takes

up more energy than it gives off and it gets very ___________ to the touch. This means that the reaction taking

place is endothermic or exothermic

10. How do you know baking a cake is a chemical reaction? ________________________________________

11. There are ___________ naturally occurring elements.

12. If elements are in the same group on the periodic table, what does that tell you? ______________________

__________________________________________________________________________________________

True or False

1. When something burns, heat & light are given off. T or F

2. Your stomach growling is an example of a chemical reaction. T or F

3. Water is 1 part hydrogen and 2 parts oxygen. T or F

4. When baking a cake, a chemical reaction takes place. T or F

5. Everything is made of chemicals. T or F

6. Alfred Nobel invented dynamite. T or F

7. You should always wear safety goggles when working with chemicals. T or F

8. Sodium chloride is better known as sugar. T or F

9. A substance can feel a little warm if the reaction is endothermic. T or F

10. When developing film, red light doesn't affect the picture. T or F

11. A cold pack gets cold because the reaction takes more energy than it gives off. T or F

12. If chemicals behave similarly, they are grouped together on the periodic table. T or F

13. Chemical reactions happen when protons link atoms together. T or F

14. When vinegar and baking soda react, oxygen is produced. T or F

15. Fireworks are not an example of chemical reactions. T or F

carbon dioxide

Sodium chlorine

fireworks

warm

cold

The ingredients (flour, milk, eggs, etc.) are changed

Explanation:

The question is incomplete, here is the complete question:

A chemist must prepare 550.0 mL of hydrochloric acid solution with a pH of 1.60 at [tex]25^oC[/tex]. He will do this in three steps: Fill a 550.0 mL volumetric flask about halfway with distilled water. Measure out a small volume of concentrated (8.0M) stock hydrochloric acid solution and add it to the flask. Fill the flask to the mark with distilled water. Calculate the volume of concentrated hydrochloric acid that the chemist must measure out in the second step. Round your answer to 2 significant digits.

Answer: The volume of concentrated hydrochloric acid solution is 1.7 mL.

Explanation:

To calculate the hydrogen ion concentration, we use the formula:

[tex]pH=-\log [H^+][/tex]

We are given:

pH = 1.60

Putting values in above equation, we get:

[tex]1.60=-\log [H^+][/tex]

[tex][H^+]=antilog (-1.60)[/tex]

[tex][H^+]=0.0251M[/tex]

To calculate the volume of concentrated solution, we use the equation:

[tex]M_1V_1=M_2V_2[/tex]

where,

[tex]M_1\text{ and }V_1[/tex] = molarity and volume of concentrated acid solution

[tex]M_2\text{ and }V_2[/tex] = molarity and volume of diluted acid solution

We are given:

[tex]M_1=8.0M\\V_1=?mL\\M_2=0.0251M\\V_2=550mL[/tex]

Putting values in above equation, we get:

[tex]8.0\times V_1=0.0251\times 550\\\\V_1=\frac{0.0251\times 550}{8.0}=1.7mL[/tex]

Hence, the volume of concentrated hydrochloric acid solution is 1.7 mL.

Answer: The empirical formula of X  is [tex]Cr_2O_3[/tex]

Explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of Cr = 68.4 g

Mass of O = 31.5 g

Step 1 : convert given masses into moles.

Moles of Cr =[tex]\frac{\text{ given mass of Cr}}{\text{ molar mass of Cr}}= \frac{68.4g}{52g/mole}=1.31moles[/tex]

Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{31.5g}{16g/mole}=1.97moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For Cr = [tex]\frac{1.31}{1.31}=1[/tex]

For O = [tex]\frac{1.97}{1.31}=1.5[/tex]

The simple whole number ratio of Cr : O= 2: 3

Hence the empirical formula is [tex]Cr_2O_3[/tex]

Answer:

O3S

Sulfur Trioxide

Explanation:

Answer:

fructose

Explanation:

because fructose is a ketonic sugar.

Answer:

40 kilograms of fuel are required to meet their energy needs for the month of April.

Explanation:

The month of April has 30 days and the full energy needed by the family is determine by the following combustion formula, derived from dimension analysis:

[tex]n\cdot Q = m\cdot L_{c}[/tex] (1)

Where:

[tex]m[/tex] - Mass of the fuel, measured in kilograms.

[tex]L_{c}[/tex] - Calorific value of the fuel, measured in kilojoules per kilogram.

[tex]Q[/tex] - Daily fuel energy, measured in kilojoules.

[tex]n[/tex] - Number of days of the month, dimensionless.

If we know that [tex]Q = 20000\,kJ[/tex], [tex]n = 30[/tex] and [tex]L_{c} = 15000\,\frac{kJ}{kg}[/tex], then the amount of fuel required to meet their energy needs for the month of April is:

[tex]m = \frac{n\cdot Q}{L_{c}}[/tex]

[tex]m = \frac{(30)\cdot (20000\,kJ)}{15000\,\frac{kJ}{kg} }[/tex]

[tex]m = 40\,kg[/tex]

40 kilograms of fuel are required to meet their energy needs for the month of April.

Answer:The potential energy of the shared elec- trons is lower in the bond than it would be if the electrons were not shared between two nuclei

Explanation:

The entire essence of chemical combination is the attainment of a lower potential energy.

When two atoms are isolated at a large distance from each other, the potential energy is high.

However as the nuclei of the two atoms approach each other, the potential energy decreases until a minimum is attained. The distance between the nuclei at this point is the bond distance.

Hence, the potential energy of the shared electrons is lower in the bond than it would be if the electrons were not shared between two nuclei.

Answer:

C)3 mole CO2 / 1 mole C3H8

Explanation:

Answer:

0.174kg of Ore are required

Explanation:

The ore of 37.3% in nickel by mass means that in 100g of ore there are 37.3g of nickel. As we need to obtain 65g of nickel we can convert this mass to mass of ore using the conversion factor (100g Ore / 37.3g Nickel) as follows:

65g of nickel * (100g Ore / 37.3g Nickel) = 174g of Ore are needed to have 65.0g of nickel. In kilograms:

174g Ore * (1kg / 1000g) =

Answer:

a. Enzymes are specific in their actions.

c. Enzymes lower the energy of activation needed for a reaction

e. Enzyme activity can be affected by temperature.

Explanation:

Enzymes are proteinous structures that acts as biological catalysts in chemical reactions that occur within a system. Like every other catalyst, which speedens the rate of chemical reactions, enzymes possess certain characteristics that makes them have the catalytic nature. They include:

- Enzymes are specific in their actions: Enzymes are substrate-specific, meaning that an enzyme can only act on a substrate it recognizes and binds to.

- Enzymes lower the energy of activation needed for a reaction: Enzymes like other catalyst speed up the rate at which a reaction occurs by lowering the activation energy needed for the reaction to take place.

- Enzyme activity can be affected by temperature: Since enzymes are proteinous i.e made of proteins, they can be easily denatured by temperature. Hence, when exposed to high temperature, enzymes can lose its shape and ultimately its function.

a. Enzymes are specific in their actions.

c. Enzymes lower the energy of activation needed for a reaction

e. Enzyme activity can be affected by temperature.

What are Enzymes?  

- Enzymes are specific in their actions: Enzymes are substrate-specific, meaning that an enzyme can only act on a substrate it recognizes and binds to.

- Enzymes lower the energy of activation needed for a reaction: Enzymes like other catalyst speed up the rate at which a reaction occurs by lowering the activation energy needed for the reaction to take place.

- Enzyme activity can be affected by temperature: As enzymes are proteinous i.e. made of proteins, they can be easily denatured by temperature. Hence, when exposed to high temperature, enzymes can lose its shape and ultimately its function.

Therefore, option a, c and e are correct.

Learn more:

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Answer:

The ricks were degraded over time by wind and water and were crushed down into tiny, smaller rocks, which is sand.

Explanation:

This is my first answer sorry im not that smart

Answer:5 to the 7th power

Explanation:

Divided 7 and y then add 4

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 5.33×10²⁴moles are in 3.21×10²⁸ molecules of Nitrogen.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity of amount of substance. It measure the number of elementary entities of a given substance that are present in a given sample.

Given number of molecules of nitrogen=3.21×10²⁸ atoms

we know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number

mole of nitrogen=given number of atoms ÷ 6.022×10²³(Avogadro number)

Substituting the values

moles of nitrogen=3.21×10²⁸ ÷ 6.022×10²³

mole of nitrogen= 5.33×10²⁴moles

Therefore, 5.33×10²⁴moles are in 3.21×10²⁸ molecules of Nitrogen.

To know more about mole, here:

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Answer:

None have backbones

No cell walls

Multicellular

Includes radial or bilateral body symmetry.

Explanation:

Answer:

SO SORRY it took so long but the answer is B :)

Explanation:

Trust me and good luck :)

The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.

Aristarchus of Samos was just a Greek astronomer that suggested the very first heliocentric model of the cosmos, wherein the sun, rather than the earth, was even at its center. Despite the fact that his hypothesis was acknowledged by other philosophers of the time, it was dismissed as unrealistic, and the geocentric model remained in use for the next 1,700 years.

Copernicus was also the first to assert that the Earth as well as the other planets orbit the sun. It was really a significant shift in thinking.

Sun can be considered as a star in solar system.

The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.

Therefore, the correct answer will be option (b).

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Answer:

the effects that the scientists are causing by manipulating varuables

Answer:

Weight is the measure of the force of gravity on an object. The mass of an object will never change, but the weight of an item can change based on its location. For example, you may weigh 100 pounds on Earth, but in outer space you would be weightless.

Explanation:

I can't see the options but I hope this helps!

Answer:

the answer is B.

I hope this helps!

Explanation:

Answer:

See explanation.

Explanation:

Hello!

In this case, since the antacid is usually composed by the following bases:

- Calcium, magnesium and aluminum hydroxides.

- Hydrogen sodium carbonate.

- Sodium carbonate.

In such a way, the feasible reactions that undergo when they react with the stomach acid are shown on the attached picture. As you can see, they all have in common the formation of chlorides and water, which are the neutralization products that calm down the acidity as they are neutral.

Best regards!

Answer:

Explanation:

p-diaminobenzene is popularly known as p-phenylenediamine. It undergoes a condensation reaction with metal halides. As a white solid (p-diaminobenzene), it can be darkened by air oxidation. The reaction showing the condensation of p-phenylenediamine with (CoCl)₂ can be seen in the image attached below.

Answer:

C. Oxygen

Explanation:

Oxygen has 8 electrons and doesn't react with fluorine noble gases

Answer:

im pretty sure its the last one

Explanation:

if plants dont have sun light they will die because the sunlight gives them the nutrients to survive

Answer:

[tex]T=16K=-256.8\°C[/tex]

Explanation:

Hello!

In this case, according to the gas laws, we would be able to assume HCl can be modeled as an ideal gas for this calculation purpose; in such a way, we use the following equation to compute the temperature:

[tex]PV=nRT\\\\T=\frac{PV}{nR}[/tex]

In such a way, we plug in moles, volume and pressure to obtain:

[tex]T=\frac{2atm*2L}{3mol*0.08206\frac{atm*L}{mol*K}}\\\\T=16K=-256.8\°C[/tex]

Best regards!

Answer:

Sulfur

Explanation:

Oxygen like sulfur would chemical react and combine with other compounds in the same way. This is because they are both located in the same group on the periodic table.

Elements in the same group have the same chemical properties and they will react the same way.

The general formula of the elements in this group are ns² np⁴.

All the elements in this group have 4 electrons in their np⁴ shell and they belong to the p-block.