Question 11

Which of the following is a trace element in the human body?

hydrogen

oxygen

zinc

nitrogen

Question 12

Which of the following statements regarding matter isfalse?

All matter is composed of elements.

All matter exists in the form of compounds.

All life is composed of matter.

All matter has mass.

Question 13

Which of the following statements best describes a compound?

A compound is exemplified by sodium.

A compound is a solution.

A compound contains two or more different elements in a fixedratio.

A compound is a pure element.

Question 14

In the equation 2 H2 + O2 ? 2 H2O,

only H2O is a compound.

only H2 and O2 are compounds.

H2, O2, and H2O are all elements.

H2, O2, and H2O are all compounds.

Question 15

Which of the following particles are found in the nucleus of anatom?

neutrons and electrons

neutrons, electrons, and protons

protons and electrons

protons and neutrons

Question 16

Which of the following best describes the atomic number of anatom?

the number of electrons in the atom

the number of protons in the atom

the number of protons, electrons, and neutrons in the atom

the number of neutrons in the atom

Question 17

Typically, nitrogen atoms are composed of electrons, protons,and neutrons. An isotope of nitrogen could

be positively charged.

be negatively charged.

have more protons than the usual nitrogen atom.

have more neutrons than the usual nitrogen atom.

Question 18

When full, the innermost electron shell of argon contains________ electrons, and the outermost shell contains ________electrons.

2; 8

8; 8

4; 8

2; 2

Question 19

A(n) ________ forms when two atoms share electrons.

covalent bond

ion

ionic bond

hydrogen bond

Question 20

A hydrogen atom has one electron. How many covalent bonds canhydrogen form?

one

none

two

four