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Understanding the Atom

Total questions: 19

Worksheet time: 14mins

Name
Class
Date
1.

In an atom, the number of protons equals the number of

a)

nuclei

b)

electrons

c)

neutrons

d)

isotopes

2.

Which particles in atoms have a negative electric charge?

a)

electrons

b)

protons

c)

neutrons

d)

nuclei

3.

During radioactive decay, atomic nuclei of unstable isotopes

a)

give off nuclear radiation

b)

are broken down by radioactive bacteria

c)

form chemical bonds

d)

are unchanged

4.

Two atoms of different elements will definitely have different numbers of

a)

nuclei

b)

protons

c)

neutrons

d)

electrons

5.

Two neutral atoms that have the same atomic number and different mass numbers are

a)

ions

b)

isotopes

c)

alpha particles

d)

different elements

6.

An ion that has a negative charge is formed when an atom

a)

loses neutrons

b)

loses electrons

c)

gains neutrons

d)

gains electrons

7.

How is Bohr's atomic model different from Rutherford's model?

a)

Bohr's model has a nucleus

b)

Bohr's model has electrons

c)

electrons in Bohr's model are located farther from the nucleus

d)

electrons in Bohr's model are located in circular energy levels

8.

An ________ is the smallest piece of an element

a)

atom

b)

proton

c)

matter

9.

All atoms of an element have the same number of

a)

protons

b)

electrons

c)

neutrons

10.

What is the smallest particle

a)

electron

b)

neutron

c)

proton

11.

Atoms of an element with different number of neutrons

a)

isotope

b)

ion

c)

radioactive

12.

What is #3

a)

proton

b)

neutron

c)

electron

d)

nucleus

13.

What is #4

a)

proton

b)

neutron

c)

electron

d)

nucleus

14.

The mass of an atom is the # of protons + ______________

a)

# of electrons

b)

# of neutrons

15.

Which part of the atom makes up most of its volume?

a)

its electron cloud

b)

its neutrons

c)

its nucleus

d)

its protons

16.

What did Dalton believe an atom was?

a)

a solid, indivisible object

b)

a tiny particle with a nucleus

c)

a nucleus surrounded by an electron cloud

d)

a tiny nucleus with electrons surrounding it

17.

What does the figure show?

a)

two different elements

b)

two different ions

c)

two different isotopes

d)

two different protons

18.

Whose model for the atom is shown?

a)

Bohr's

b)

Dalton's

c)

Rutherford's

d)

Thomson's

19.

Which is true about the size of an atom?

a)

It can only be seen using a scanning tunneling microscope.

b)

It is about the size of the period at the end of this sentence.

c)

It is large enough to be seen using a magnifying lens.

d)

It is too small to see with any type of microscope.