5.3

Question 1

Why can’t scientists measure the diameter of a single atom?

Answer 1

Atoms have no well-defined border

Question 2

What do you need to figure out the size of atoms?

Answer 2

Two atoms

Question 3

Define atomic radius

Answer 3

Half the distance between the nuclei of two atoms when they are joined in a molecule

Question 4

Atomic radius is measured in

Answer 4

Picometers

Question 5

Molecules that can’t be single atoms will be found in

Answer 5

Diatomic molecules

Question 6

Elements that are only found in diatomic molecules

Answer 6

Hydrogen
Oxygen
Nitrogen
Fluorine
Chlorine
Bromine
Iodine
Everything except the first form a 7

Question 7

Atomic radius ______ from top to bottom in a group

Answer 7

Increases

Question 8

Atomic radius ______ from left to right across a period

Answer 8

Decreases

Question 9

The difference in size as you go down a group is _______ than the difference as you go across a period

Answer 9

Greater

Question 10

What are shielding electrons?

Answer 10

Inner core electrons

Question 11

Atomic radius increases down a group because

Answer 11

The shielding effect of going down another energy level is greater than the effect of increasing protons

Question 12

Atomic radius decreases across a period because

Answer 12

Within a period, shielding effect doesn’t change, so as the number of protons increases, the electrons are pulled closer and atomic size decreases

Question 13

Ion

Answer 13

Atom or group of atoms that has a positive or negative charge, created by the transfer of electrons

Question 14

Metallic elements _____ one or more electrons from highest energy level to make ______ charge ions

Answer 14

Lose

Positive

Question 15

Cation

Answer 15

Ion with a positive charge

Decreases in size

Question 16

Nonmetallic elements ____ one or more electrons to make _______ charge ions

Answer 16

Gain

Negative

Question 17

Anion

Answer 17

Ion with a negative charge

Increases in size

Question 18

Why do atoms form ions?

Answer 18

To become more stable like a noble gas

Question 19

Ionization energy

Answer 19

Energy required to remove an electron from an atom to make a positive ion

Question 20

Ionization energy _______ as you go down a group

Answer 20

Decreases

Question 21

Ionization energy ______ from left to right across a period

Answer 21

Increases

Question 22

1st ionization energy

Answer 22

Energy to remove first outermost electron

Question 23

How can ionization energies be used to predict charges of cations?

Answer 23

Easy to remove first electron from group 1A metal atoms=little IE
Difficult to remove second electron=big IE
Group 1A metals tend to form cations with a 1+ charge because it wants to be like a noble gas

Question 24

Why is first ionization energy of nonmetal much higher than alkali metal?

Answer 24

Number of protons increases while shielding stays constant, so it’s more difficult to remove an electron

Question 25

Ionization energy decreases down a group because

Answer 25

Increases energy level= increases size=easier to remove an electron from atom so lower ionization energy

Question 26

Ionization energy increases across a period because

Answer 26

Increases in protons/charge but no change in shielding means higher ionization energy

Question 27

Metals lose electrons and ______ in size

Answer 27

Decrease

Question 28

Nonmetals gain electrons and ______ in size

Answer 28

Increase

Question 29

Size graph in a period

Answer 29

That backwards N shape from the worksheet
First leg (low and decreasing) is cations
Last leg (high and decreasing) is anions

Question 30

Electronegativity

Answer 30

Ability of an atom to attract electrons when it’s bonded to another atom

Question 31

Electronegativity ________ down a group because

Answer 31

Decreases because bigger atoms have a harder time attracting the outermost electrons

Question 32

Electronegativity ________ across a period in

Answer 32

Increases

In representative elements

Question 33

Metals have a ___ value of Electronegativity

Answer 33

Low

Question 34

Nonmetals have a _____ value of Electronegativity except for

Answer 34

High except noble gases