Answer:i nitrogen, oxygen, hydrogen
Explanation: " Molecules of most elements are made up of only one of atom of that element" well if you search it up
Answer:
Everything that has mass and takes up space is matter. Every day, you encounter phenomena that either don't have mass or don't take up space. They are non-matter. Basically, any type of energy or any abstract concept is an example of something that is not matter.
An apple.
A person.
A table.
Air.
Water.
A computer.
Paper.
Iron.
hope this helped you
Answer is 3Mg + N2 —--> Mg3 N2
<u>Answer:</u> The mass of nitrogen gas reacted to produce given amount of energy is 5.99 grams.
<u>Explanation:</u>
The given chemical reaction follows:

We know that:
Molar mass of nitrogen gas = 28 g/mol
We are given:
Enthalpy change of the reaction = 14.2 kJ
To calculate the mass of nitrogen gas reacted, we use unitary method:
When enthalpy change of the reaction is 66.4 kJ, the mass of nitrogen gas reacted is 28 grams.
So, when enthalpy change of the reaction is 14.2 kJ, the mass of nitrogen gas reacted will be = 
Hence, the mass of nitrogen gas reacted to produce given amount of energy is 5.99 grams.