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3 years ago

When you are balancing chemical reactions (equations'), what must you never touch?

Chemistry

1 answer:

Minchanka [31]3 years ago

4 0

The correct answer option is: the number in subscript.

When you are balancing any chemical equation, you must never touch or change the number in subscript of the molecule of a chemical or compound as it will upset the composition.

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1) List the number of protons, neutrons, and electrons in Carbon-13.

ser-zykov [4K]

1) Carbon-13:
Proton-6 Neutron-7 Electron-6

2)Atomic mass of element X:
(55*10+56*20+57*70)/100=56.6

4 0

3 years ago

Which of the following is the most common gas in the troposphere

Effectus [21]

The most common gas in the troposphere is nitrogen.

I hope this helps!

7 0

3 years ago

Read 2 more answers

What is the function of stomata in plants?

melomori [17]

Answer:

Small holes in plants that allow carbon dioxide in and oxygen and water vapor out

Explanation:

Stomata are tiny holes that open and close for the plant to breathe.

6 0

3 years ago

Assuming an electron is a hydrogen atom can undergo any of the transitions below, thus changing its energy. Which transition is

inn [45]

Answer:

n = 3 to n = 5

Explanation:

According to the Bohr's model of the atom, electrons in an atom absorb energy to move from a lower to higher energy level.

We must note that as we progress away from the nucleus, the energy levels of electrons become closer together. The energy difference between successive levels decreases and the wavelength of light associated with such transitions become longer.

Hence,the absorption of light of the longest wavelength corresponds to n = 3 to n = 5

5 0

3 years ago

Urea, (NH2)2CO, is a product of metabolism of proteins. An aqueous solution is 37.2% urea by mass and has a density of 1.032 g/m

Feliz [49]

Answer:

The molarity of urea in this solution is 6.39 M.

Explanation:

Molarity (M) is <em>the number of moles of solute in 1 L of solution</em>; that is

$molarity = moles of solute ÷ liters of solution$

To calculate the molality, we need to know the number of moles of urea and the volume of solution in liters. We assume 100 grams of solution.

Our first step is to calculate the moles of urea in 100 grams of the solution,

using the molar mass a conversion factor. The total moles of 100g of a 37.2 percent by mass solution is

60.06 g/mol ÷ 37.2 g = 0.619 mol

Now we need to calculate the volume of 100 grams of solution, and we use density as a conversion factor.

1.032 g/mL ÷ 100 g = 96.9 mL

This solution contains 0.619 moles of urea in 96.9 mL of solution. To express it in molarity, we need to calculate the moles present in 1000 mL (1 L) of the solution.

0.619 mol/96.9 mL × 1000 mL= 6.39 M

Therefore, the molarity of the solution is 6.39 M.

4 0

3 years ago