Chemistry Essentials Mid-Class Review

Question 1

A control in an experiment

Accepted Answer

allows the scientist to identify the cause of&#13;the results in an experiment

Question 2

Matter that has a definite shape and a definite volume is

Accepted Answer

a solid.

Question 3

If the temperature outside is 26°C, the temperature would be ______ K.

Accepted Answer

299

Question 4

Which of the following measurements contains three significant figures?

Accepted Answer

20.2 mL

Question 5

Because the noble gases have a stable electron configuration, they have

Accepted Answer

high ionization energies.

Question 6

Matter can be defined as anything that

Accepted Answer

has mass and volume.

Question 7

Which of the following represents an electron configuration for a calcium atom, whose atomic number is 20?

Accepted Answer

1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

Question 8

How many neutrons are present in an atom of tin that has an atomic number of 50 and a mass number of 119?

Accepted Answer

69

Question 9

A compound differs from a mixture in that a compound

Accepted Answer

has a definite composition by mass of the elements it contains.

Question 10

The equation E = mc² shows that

Accepted Answer

mass and energy are related.

Question 11

The periodic law states that

Accepted Answer

the chemical properties of elements can be grouped based on periodicity.

Question 12

Mg + 2HCl -> MgCl2 + H2 Which of the following represents the reactants in this reaction?

Accepted Answer

Mg and 2HCl

Question 13

As an electron in an excited state returns to its ground state,

Accepted Answer

light energy is emitted.

Question 14

Which of the following is not part of the scientific method?

Accepted Answer

introducing bias

Question 15

The number of protons of an atom equals

Accepted Answer

the number of electrons.

Question 16

A measurement of 23,465 mg converted to grams equals

Accepted Answer

234.65 g.

Question 17

According to quantum theory, an electron

Accepted Answer

exists around the nucleus only in certain, well-defined orbital.

Question 18

The accuracy of a measurement

Accepted Answer

is how close it is to the true value.

Question 19

An important result of Rutherford’s work was to establish that

Accepted Answer

the atom is mostly empty space.

Question 20

All measurements in science

Accepted Answer

have some degree of uncertainty.

Question 21

Which of the following pairs of measurements are equal?

Accepted Answer

325 mg and 0.325 g

Question 22

All elements in Group 2

Accepted Answer

are known as the alkaline-earth metals.

Question 23

Which of the following is not a main-group element?

Accepted Answer

neon

Question 24

A metal sample has a mass of 45.65 g. The volume of the sample is 16.9 cm³. The density of the sample is

Accepted Answer

2.70 g/cm³.

Question 25

In the modern periodic table, elements are arranged according to

Accepted Answer

increasing atomic number.

Question 26

To be classified as a metal, an element must

Accepted Answer

conduct electricity.

Question 27

Which of the following is an element?

Accepted Answer

He

Question 28

A theory differs from a hypothesis in that a theory

Accepted Answer

has been subjected to experimental testing.

Question 29

_________ is the element with the &#13;highest electronegativity.

Accepted Answer

Fluorine

Question 30

Which of the following is best classified as a homogeneous mixture?

Accepted Answer

Hot Tea

Question 31

As electrons are added to the outer energy levels of atoms within a period, the atoms generally have

Accepted Answer

decreasing radii and increasing ionization energies.

Question 32

A chemical property of a substance

Accepted Answer

depends on how the substance reacts with other substances.

Question 33

The SI base unit that is commonly used in chemistry to describe the amount of a substance is the

Accepted Answer

gram.

Question 34

Isotopes of an element differ in their

Accepted Answer

numbers of neutrons.

Question 35

Determine which of the following measurements is the largest.

Accepted Answer

0.0200 kL

Question 36

The energy it takes to remove an electron from an atom _____ as you move left to right across a period, from Mg to Cl.

Accepted Answer

generally increases

Question 37

Group 17 elements, the halogens, are the most reactive of the nonmetal elements because they

Accepted Answer

require only one electron to fill their &#13;outer energy level.

Chemistry Essentials Mid-Class Review

Questions 37

Chemistry Essentials Mid-Class Review

Questions 37