Question

question 7
4al₂(co₃)₃

of molecules is

of elements is

there are aluminum atoms
there are carbon atoms
there are oxygen atoms

Explanation:

Step1: Determine number of molecules

The coefficient in front of the chemical formula represents the number of molecules. Here the coefficient is 4, so there are 4 molecules.

Step2: Identify elements

The elements present are Al (aluminum), C (carbon) and O (oxygen), so there are 3 elements.

Step3: Calculate aluminum atoms

There are 2 Al atoms in one $Al_2(CO_3)_3$ unit and 4 units in total. So the number of Al atoms is $4\times2 = 8$.

Step4: Calculate carbon atoms

There are 3 C atoms in one $Al_2(CO_3)_3$ unit and 4 units in total. So the number of C atoms is $4\times3=12$.

Step5: Calculate oxygen atoms

There are 3 carbonate ($CO_3$) groups in one $Al_2(CO_3)_3$ unit, and each carbonate group has 3 O atoms. So one $Al_2(CO_3)_3$ unit has $3\times3 = 9$ O atoms. With 4 units in total, the number of O atoms is $4\times9 = 36$.

Answer:

of molecules is 4

of elements is 3

There are 8 Aluminum atoms
There are 12 Carbon atoms
There are 36 Oxygen atoms