Question

2.3 identify each of the following as either an atom, element, molecule or compound:
substance atom, element, molecule, or compound
a. nh₃
b. p
c. carbon - 14
d. s
e. p₄

Explanation:

Step1: Recall definitions

An atom is the smallest unit of an element. An element is a pure substance made of only one type of atom. A molecule is a group of two or more atoms held together by chemical bonds. A compound is a substance made up of two or more different elements chemically combined.

Step2: Analyze a. $NH_3$

$NH_3$ is made up of nitrogen (N) and hydrogen (H) atoms chemically combined, so it is a compound.

Step3: Analyze b. P

P represents the element phosphorus. It can refer to a single - atom of phosphorus or the element in general, so it is an element.

Step4: Analyze c. carbon - 14

Carbon - 14 is a specific isotope of carbon. It is an atom.

Step5: Analyze d. S

S represents the element sulfur. It can refer to a single - atom of sulfur or the element in general, so it is an element.

Step6: Analyze e. $P_4$

$P_4$ is a group of four phosphorus atoms held together by chemical bonds, so it is a molecule.

Answer:

a. Compound
b. Element
c. Atom
d. Element
e. Molecule