Unit 3 Exam

Question 1

Which contribution is a modification to Thomson’s plum pudding model?

Answer 1

A positively charged nucleus sits at the center of an atom.

Question 2

An atom with 4 protons, 5 neutrons, and 4 electrons has an atomic mass of

Answer 2

9 amu

Question 3

Which of the following statements does not describe the structure of an atom?

Inside the nucleus of an atom are protons and neutrons.
Protons are positively charged sub-atomic particles.
Electrons are negatively charged sub-atomic particles.
Most of the mass of an atom comes from the electron cloud.

Answer 3

Most of the mass of an atom comes from the electron cloud.

FALSE

Question 4

There are more electrons than protons in a negatively charged atom. T/F?

Answer 4

True

Question 5

A neutral atom of aluminum has 13 protons and how many electrons

Answer 5

13

Question 6

Which of the following elements has the highest atomic mass?
Helium: 2 protons and 2 neutrons
Nitrogen: 7 protons and 7 neutrons
Oxygen: 8 protons and 8 neutrons
Hydrogen: 1 proton and no neutrons

Answer 6

Oxygen: 8 protons and 8 neutrons

Question 7

Ernest Rutherford

Answer 7

Positively charged nucleus

Question 8

J.J. Thomson

Answer 8

Plum pudding model

Question 9

John Dalton

Answer 9

Atoms indivisible

Question 10

James Chadwick

Answer 10

Discovery of neutrons

Question 11

Which of the following elements has the largest atomic radius?
Silicon	
Aluminum
Sulfur
Phosphorous

Answer 11

Aluminum

Question 12

Which of the following elements is the most reactive? 
Beryllium
Calcium
Magnesium
Barium

Answer 12

Barium

Question 13

Neon

Answer 13

Nonreactive gas

Question 14

Boron

Answer 14

Has properties of both metals and nonmetals

Question 15

Barium

Answer 15

Great conductor of heat and electricity

Question 16

Potassium

Answer 16

Malleable and highly reactive

Question 17

A neutral atom of beryllium (Be) has an average mass of 9 amu and 4 electrons. How many neutrons does it have?

Answer 17

5

Question 18

The element chlorine is represented by the symbol

Answer 18

Cl

Question 19

Use your periodic table of elements. Take any element from the first column, except for hydrogen and lithium, and answer the following questions:

What is the element’s name and symbol?
Is it a metal, nonmetal, or metalloid?
Which family does it belong to?
How many protons, neutrons, and electrons does its neutral atom have?

Francium

Answer 19

1. Fr, Francium
2. Francium is a non-metal
3. Francium belongs to the alkali metal family.
4. Francium 87 Protons, 136 Neutrons, 87 Electrons

Question 20

Which item is made from a basic ingredient?

Answer 20

Toothpaste

Question 21

Which description is not a property of a base?

Turns litmus paper red
Bitter taste
Caustic
pH higher than 7

Answer 21

Turns litmus paper red

Question 22

Ion

Answer 22

An atom or molecule that has a positive or negative charge

Question 23

Acid

Answer 23

A compound that increases hydrogen ions (H+) when it is dissolved in a solution

Question 24

Alkaline

Answer 24

A compound that increases the hydroxide ions (OH−) when it is dissolved in a solution

Question 25

pH

Answer 25

A value from 0 to 14 that is used to specify how acidic or basic a compound is when it is dissolved in water

Question 26

Which description is not a property of an acid? Sour taste Corrosive Slimy feel Dissolves metals

Answer 26

Slimy feel

Question 27

Which number represents an acidic pH, 4 or 9

Answer 27

4

Question 28

Which description of salt is a physical property? No combustion Makes ionic bonds Product of mixing acids and bases Solid does not conduct electricity

Answer 28

Solid does not conduct electricity

Question 29

Which substances will make a salt when combined? Vinegar and antacids Soda and wine Soap and ammonia Fertilizer and detergent

Answer 29

Vinegar and antacids

Question 30

Which of the following techniques can be used to separate a homogeneous mixture into its component parts?

Answer 30

Apply pressure

Question 31

Heterogeneous mixtures can be physically separated into their individual components. T/F?

Answer 31

True

Question 32

Heterogeneous

Answer 32

Mixture that has its different components mixed unevenly within the substance

Question 33

Colloid

Answer 33

A mixture in which microscopically insoluble particles are suspended throughout another substance

Question 34

Emulsion

Answer 34

A mixture in which two or more liquids are mixed that normally are not mixable

Question 35

Homogeneous

Answer 35

Mixture that has its different components mixed evenly within the substance

Question 36

What makes a pure substance different from a heterogeneous mixture?

Answer 36

The components of a pure substance are single elements or compounds instead of a mixture of compounds.

Question 37

The process of filtration was used to separate a sample into its components. What conclusion about the sample can be formed based on the technique used?

Answer 37

It was a heterogeneous mixture.

Question 38

Which substance is a heterogeneous mixture Cereal Silver Nickel Shampoo

Answer 38

Cereal