Question

learning check

1. a) what does the subscript in a chemical formula indicate?

b) what does having no subscript mean?

1. for the compound ammonia, nh₃, how many nitrogen atoms are there, and how many hydrogen atoms are there in each molecule?
2. write the chemical formula for a compound that is made of one atom of carbon (c) and four atoms of hydrogen (h).
3. write the chemical formula for a compound that has two atoms of nitrogen and four atoms of oxygen.

Explanation:

Step1: Define subscript meaning

The subscript in a chemical formula indicates the number of atoms of the element it follows.

Step2: Explain no - subscript case

Having no subscript means there is 1 atom of that element.

Step3: Analyze ammonia formula

For $NH_3$, the subscript of $N$ is 1 (implied when no subscript is shown), so there is 1 nitrogen atom. The subscript of $H$ is 3, so there are 3 hydrogen atoms.

Step4: Write carbon - hydrogen compound formula

A compound with 1 carbon atom and 4 hydrogen atoms has the formula $CH_4$.

Step5: Write nitrogen - oxygen compound formula

A compound with 2 nitrogen atoms and 4 oxygen atoms has the formula $N_2O_4$.

Answer:

1. a) The number of atoms of the element it follows.

b) There is 1 atom of that element.

1. 1 nitrogen atom; 3 hydrogen atoms.
2. $CH_4$
3. $N_2O_4$