The carbon atom is sometimes listed as carbon-12 and sometimes as carbon-14. What does this mean?

A.
These are two isotopes of the carbon atom. Carbon-12 has 6 neutrons and carbon-14 has 8 neutrons.

B.
These are two isotopes of the carbon atom. Carbon-12 has 6 protons and carbon-14 has 8 protons.

C.
These are two allotropes of the carbon atom. Carbon-12 has 6 neutrons and carbon-14 has 8 neutrons.

D.
These are two allotropes of the carbon atom. Carbon-12 has 6 protons and carbon-14 has 8 protons.

Question

The carbon atom is sometimes listed as carbon-12 and sometimes as carbon-14. What does this mean? 	
	
 
A.
	These are two isotopes of the carbon atom. Carbon-12 has 6 neutrons and carbon-14 has 8 neutrons.
	
 
B.
	These are two isotopes of the carbon atom. Carbon-12 has 6 protons and carbon-14 has 8 protons.
	
 
C.
	These are two allotropes of the carbon atom. Carbon-12 has 6 neutrons and carbon-14 has 8 neutrons.
	
 
D.
	These are two allotropes of the carbon atom. Carbon-12 has 6 protons and carbon-14 has 8 protons.

anonymous · Answer

Allotropes are structural differences in a way that an element combines. For example, graphite (used in pencils to write) and diamond are both carbon based, but they have difference structures. So the last two are not the answer.
Isotopes, however, are elements that simply differ in the amount of NEUTRONS, not PROTONS. So the answer is A.

anonymous · Answer

Thanks