Which of the following is not one of the major elements

present in the human body?

a$.$ oxygen

b$.$ carbon

$2$ iron

d$.$ hydrogen

Which of the following is not a subatomic particle?

a$.$ proton

b$.$ electron

$($c$)$ isotope

d$.$ neutron

The total number of electrons in an atom equals the number

of:

a$.$ neutrons in its nucleus.

b$.$ electrons in its nucleus.

c$.$ protons in his nucleus.

d$.$ ions in its nucleus.

An atom can be described as chemically stable if its

outermost electron shell contains:

a$.$ three electrons.

b$.$ five electrons.

c$.$ six electrons.

d$.$ eight electrons.

Isotopes are atoms of elements that differ in their number

of:

a$.$ protons

b$.$ electrons

c$.$ neutrons

d$.$ nuclei

Ionic bonds are chemical bonds formed by the:

a$.$ sharing of electrons between atoms.

donation of protons from one atom to$.$

c$.$ transfer of electrons from one atom to another.

called:

a$.$ ionic.

b$.$ covalent.

c$.$ hydrogen.

d$.$ electronic.

True or False

$8$

Matter is term used by chemists to describe all the

materials or substances

around us$.$

Mass number refers to the number of protons plus of

the number of neutrons in the atom's nucleus.

Sodium chloride is an example of a covalent bond.