Question

the molecular formula is c₆h₁₂o₆ because one molecule actually co
for the following compounds determine the number of atoms of ea
formula | numbers of atoms
cacl₂ | ca = 1; cl = 2
co₂ |
h₂o |
baso₄ |
k₂o |
naf |
naf |
na₂co₃ |

Explanation:

Step1: Identify atoms in $\text{CO}_2$

No subscript = 1; subscript = atom count.
$\text{C}=1; \text{O}=2$

Step2: Identify atoms in $\text{H}_2\text{O}$

Subscript applies only to preceding atom.
$\text{H}=2; \text{O}=1$

Step3: Identify atoms in $\text{BaSO}_4$

Subscript 4 applies to O only.
$\text{Ba}=1; \text{S}=1; \text{O}=4$

Step4: Identify atoms in $\text{K}_2\text{O}$

Subscript 2 applies only to K.
$\text{K}=2; \text{O}=1$

Step5: Identify atoms in $\text{NaF}$

No subscripts mean 1 atom each.
$\text{Na}=1; \text{F}=1$

Step6: Repeat for duplicate $\text{NaF}$

Same as Step5, no change.
$\text{Na}=1; \text{F}=1$

Step7: Identify atoms in $\text{Na}_2\text{CO}_3$

Subscripts apply to respective atoms.
$\text{Na}=2; \text{C}=1; \text{O}=3$

Answer:

Formula	Numbers of atoms
$\text{CO}_2$	$\text{C}=1; \text{O}=2$
$\text{H}_2\text{O}$	$\text{H}=2; \text{O}=1$
$\text{BaSO}_4$	$\text{Ba}=1; \text{S}=1; \text{O}=4$
$\text{K}_2\text{O}$	$\text{K}=2; \text{O}=1$
$\text{NaF}$	$\text{Na}=1; \text{F}=1$
$\text{NaF}$	$\text{Na}=1; \text{F}=1$
$\text{Na}_2\text{CO}_3$	$\text{Na}=2; \text{C}=1; \text{O}=3$