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Atoms, Atomic Theory, Isotopes, and Chemical Reactions

Total questions: 20

Worksheet time: 5mins

Name
Class
Date
1.

Isotopes of an element have a different number of...

a)

Mass Number

b)

Protons

c)

Neutrons

d)

Electrons

2.

Potassium-39 has how many neutrons?

(a)  

3.

Bromine-80 has how many protons?

(a)  

4.

Which of the following shows an element with 76 protons and 114 neutrons?

a)

Arsenic - 190

b)

Arsenic - 114

c)

Osmium - 190

d)

Osmium - 114

5.

Which element has 12 protons and 13 neutrons?

a)

Magnesium

b)

Carbon

c)

Aluminum

d)

None of these answer choices.

6.

Rubidium has two common isotopes, 85Rb and 87Rb. If the abundance of 85Rb is 72.2% and the abundance of 87Rb is 27.8%, what should the relative atomic mass (or average atomic mass) of Rubidium be? (HINT: Use your periodic table)

a)

85.468 amu

b)

37 amu

c)

85.6 amu

d)

86.4 amu

7.

How do you calculate mass number?

a)

Protons - Electrons

b)

Protons + Neutrons

c)

None of these answers.

d)

Neutrons + Protons

8.

The smallest unit of a pure substance that has the properties of that substance is widely known as a(n) (a)   ?

9.

Atoms are made up of three basic parts, which are -

(a)  

10.

What scientist is best known for his "Plum Pudding" model of the atom?

(a)  

11.

An atom's overall charge is ________.

a)

Depends

b)

Neutral

c)

Positive

d)

Negative

12.

Rutherford's gold foil experiment provided evidence that...

a)

negative and positive charges are spread evenly throughout the atom.

b)

alpha particles have a positive charge.

c)

gold is not a dense as previously thought.

d)

there is a dense positively charged nucleus at the center of an atom.

13.

If a chemical reaction is EXOTHERMIC, the temperature surrounding the chemical reaction would....

a)

Increase

b)

Decrease

c)

Stay the same

14.

If a chemical reaction is endothermic, the temperature surrounding the chemical reaction would...

a)

Increase

b)

Decrease

c)

Stay the same

15.

Select the answer which correctly names the reaction as well as correctly classifies the way energy is involved in this process.

a)

photosynthesis ; exothermic

b)

cellular respiration ; exothermic

c)

cellular respiration ; endothermic

d)

photosynthesis ; endothermic

16.

What instrument would you use to detect an endothermic or exothermic reaction?

a)

Thermometer

b)

Ruler

c)

Triple-Beam Balance

17.

Which of the following is a sign that a chemical reaction has occurred?

a)

Eruption or formation of bubbles

b)

change in shape

c)

expanding to occupy a larger, bigger volume

d)

change in density

18.

Which of the following is a sign that a physical reaction has occurred?

a)

Eruption or formation of bubbles

b)

change in temperature

c)

expanding to occupy a larger, bigger volume

d)

change in chemical formula

19.

 According to the following chemical reaction 2Mg + O2 ---> 2MgO, which are the reactants?

a)

Mg and O2O_2

b)

MgO

c)

Mg and MgO

d)

O and MgO

20.

According to the following chemical reaction, which is considered a product?

a)

carbon dioxide - CO2CO_2

b)

Glucose - C6H12O6C_6H_{12}O_6

c)

Oxygen - O2O_2

d)

None of these choices