Represents number of atoms in a chemical formula?

Answer 1

Just add 'em up.

Example: 4-4'-methylene diphenyl diisocyanate, which is used to make polyurethane. (I could have picked something real common like water (3 atoms) or glucose (24 atoms) but I wanted to make this fun...) Its formula is:

C15H10N2O2

So we have:

15 carbon atoms

10 hydrogen atoms

2 nitrogen atoms

2 oxygen atoms

Or 29 atoms total.

Answer 2

The numbers below and to the right of the chemical symbol is called the subscript. The subscript only refers to the atom it follows. So take for example:

H2O

The 2 only refers to the H meaning that there are two hydrogen atoms. When there is no subscript, it is assumed to be 1. So in our example there would be only 1 oxygen. In the above example, putting it all together we have 2 hydrogen and 1 oxygen or 3 atoms total.

Sometimes you encounter another number called the coefficient which is found in the front of the molecule such as:

3H2O

When there is a coefficient you multiply everything in the molecule by the coefficient. So instead of 2 hydrogen atoms its 3 * 2 or 6 hydrogen atoms. Similarly there are 3 *1 or 3 oxygen atoms. Putting it all together we have 6 H and 3 O or 9 atoms total. Notice that it is 3X the amount before we multiplied by the coefficient.

Those are the basic rules. There are a few more but I suspect this will get you by.

Answer 3

Each atomic symbol (like 'O', 'H', 'Pb', 'Cu' etc) represents 1 atom of that element. where more than one atom of that element is involved in a molecule, then the number of atoms is given as a suffix thus:-

H2O (Water) is made of 2 atoms of hydrogen and 1 atom of Oxygen, making 3 atoms in all.

Similarly C6H6 (Benzene) is made of 6 Carbon atoms and 6 Hydrogen atoms making 12 atoms in all.

Let us have Nitro-aniline which is C6H4(NO2)NH2 So start with C - there are 6 carbons. Hydrogens there are 4+ 2 =6. Nitrogens -there are 2. Oxygens there are 2.

So the total number of atoms in nitroaniline is 6+6+2+2 = 16.

Answer 4

The number of atoms in a chemical formula is indicated by the subscripts. Add the subscripts for all of the elements together to get the total number of atoms in a chemical formula.

Answer 5

You can tell how many atoms are in a formula by looking at the number of electrons or by the number of protrons.

Answer 6

say it was C6H12O6 you would just look at the letters for the elements and add up the numbers of each element.

Answer 7

As many as necessary to give the total number(s) of atoms of each element present in the compound that the formula represents.

Answer 8

There are 2 atoms of hydrogen in a chemical formula.

Answer 9

There are two stable molecules of oxygen. Oxygen molecule has 2 oxygen atoms. An ozone molecule has three oxygen atoms.

Answer 10

It depends on the chemical compound you consider. For example a hydrogen molecule has two hydrogen atoms. A methane molecule has four hydrogen atoms (around a carbon atom).