Homework Practice

Printable assignment

Atomic Data: Number, Mass, Isotopes and Symbols

Section A: Atomic Number and Mass Number

Question 1mcq

Atomic number equals number of:

A.Electrons + neutrons always

B.Neutrons only

C.Protons + neutrons

D.Protons

Question 2mcq

Mass number equals:

A.Only protons

B.Only shells

C.Only electrons

D.Protons + neutrons

Question 3mcq

An atom has atomic number 6 and mass number 12. Number of neutrons is:

A.18

B.6

C.0

D.12

Question 4mcq

A neutral atom of sodium has atomic number 11. It has electrons:

A.11

B.12

C.10

D.22

Question 5mcq

An atom has 17 protons and 18 neutrons. Its mass number is:

A.18

B.17

C.1

D.35

Question 6mcq

If two atoms have different atomic numbers, they are:

A.Same element always

B.Isotopes always

C.Same atom

D.Different elements

Section B: Isotopes, Isobars and Symbols

Question 7mcq

Isotopes have same atomic number but different:

A.Chemical symbol always

B.Number of protons

C.Element identity

D.Mass number

Question 8mcq

^{35}Cl

and

^{37}Cl

are:

A.Isobars

B.Ions only

C.Different elements with same mass

D.Isotopes

Question 9mcq

Isobars have same:

A.Number of protons always

B.Chemical properties always

C.Mass number

D.Atomic number

Question 10mcq

The symbol for sodium is:

A.So

B.Sd

C.S

D.Na

Question 11mcq

The symbol for potassium is:

A.Pt

B.Po

C.K

D.P

Question 12mcq

Which pair is correctly matched?

A.Argon — Ag

B.Chlorine — C

C.Carbon — Ca

D.Calcium — Ca