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Atomic Theory & Structure

Total questions: 15

Worksheet time: 8mins

Name
Class
Date
1.

In Bohr's model of the atom, where are the electrons located?

a)

in the center of the atom

b)

in energy levels outside the nucleus

c)

spread throughout the atom, like a chocolate chip cookie

2.

Which part(s) of Dalton's atomic theory are false? Check all that apply.

a)

Atoms are indivisible (cannot be divided).

b)

Atoms of different elements can chemically combine to form compounds.

c)

During chemical reactions, atoms are rearranged, but never created or destroyed.

d)

Atoms of the same element are identical.

3.

Why is an atom considered electrically neutral?

a)

The number of protons equals the atomic number.

b)

The number of electrons equals the number of neutrons.

c)

The number of protons is the same as the number of electrons.

d)

The number of electrons equals the number of protons.

4.

Based on the gold foil experiment, what did Rutherford conclude about the atom. Check all that apply.

a)

The electrons orbit in definite paths around the nucleus.

b)

The atom contains a central, positively charged nucleus.

c)

It is impossible to know an electron's location and its speed at the same time.

d)

The atom is mostly empty space.

5.

JJ Thomson used his cathode ray tube experiments to discover --

a)

a negatively charged particle called an electron

b)

a positively charged particle called a proton

c)

alpha particles

d)

a neutral particle called a neutron

6.

A subatomic particle with a neutral charge is called

a)

a proton

b)

an isotope

c)

an electron

d)

a neutron

7.

__________ determine the chemical reactivity of an atom.

a)

Protons

b)

Electrons

c)

Isotopes

d)

Neutrons

8.

An atom with the same atomic number but a different mass number is called

a)

an ion

b)

an isotope

c)

an element

9.

__________ are used to identify the element.

a)

Electrons

b)

Periodic Table

c)

Protons

d)

Neutrons

10.

If you change the number of neutrons, you change the __________.

a)

charge

b)

mass

c)

identity

11.

The mass number of an isotope is equal to

a)

the number of protons.

b)

the number of protons minus the number of neutrons.

c)

the number of protons plus the number of neutrons.

d)

the number of neutrons.

12.

How many protons are in Carbon-14?

a)

6

b)

8

c)

14

d)

12

13.

How many neutrons are in Lithium-7?

a)

4

b)

3

c)

7

d)

5

14.

An isotope contains 19 protons and 21 neutrons. What is it called?

a)

Potassium-21

b)

Potassium-40

c)

Calcium-20

d)

Calcium-40

15.

An isotope of carbon contains 7 neutrons. What is it's mass number?

a)

7

b)

12

c)

6

d)

13