Chapter 6 Test

Question 1

What is ionization energy?

Answer 1

The amount of energy required to remove an electron from an atom or ion. (This forms a positive ion.)

Question 2

State the trends for electron affinity. Don’t forget the exceptions! b. Explain why it has these trends.

Answer 2

a. Electron affinity increases (becomes more negative) across a period and decreases down a group. The exception is the noble gases, which have little or no electron affinity. B. Electron affinity increases across a period because protons are being added to the nucleus. This makes the nucleus more positive, which gives it a greater attraction for electrons. This means that it’s easier for an atom to gain a new electron. It decreases down a group because electron shielding blocks the nucleus, so it can’t attract new electrons as easily. Also, the electrons are farther from the nucleus, where the pull from the nucleus isn’t as strong.

Question 3

Explain what “Coulomb’s law” is.

Answer 3

The closer opposite charges are to one another, the stronger the attraction between them is. The farther apart opposite charges are, the weaker the attraction.

Question 4

11. List one property of the actinides. Where are the actinides?

Answer 4

Nuclear structures are more important than electron configurations, all are radioactive. Located in first row of f-block, or element #90-103.

Question 5

List two properties of metalloids.

Answer 5

Semiconductors, conduct better than nonmetals but not as well as metals, solid at room temp.

Question 6

36. What is electron affinity?

Answer 6

The energy emitted upon the addition of an electron to an atom or group of atoms in the gas phase. (More neg. e- affin. Means more energy is given off, which means the atom has a stronger attraction for new electrons.)

Question 7

State the trends for ionization energy. b. Explain why it has these trends.

Answer 7

Ionization energy increases across a period and decreases down a group. B. Ionization energy increases across a period because protons are being added to the nucleus. This makes the nucleus more positive, which gives it a greater attraction for electrons. This means that it’s harder (takes more energy) to remove an electron. It decreases down a group because electron shielding blocks the nucleus, so it doesn’t hold onto electrons as strongly. Also, the electrons are farther from the nucleus, so they are easier to remove (it takes less energy to remove them).

Question 8

State two properties of noble gases.

Answer 8

all gases, very low reactivity, full outer energy level

Question 9

41. Why don’t noble gases fit the trend?

Answer 9

The already have a full outer energy level (stable octet of electrons) so they don’t want to add any new electrons. If you were to add a new electron to a noble gas, you would have to start an entire new energy level.the noble gases have the lowest (most positive) electron affinity. (Remember, electron affinity is negative.)

Question 10

32. What does it mean to say that something is periodic?

Answer 10

It has a repeating pattern.

Question 11

Explain why ionization energy and electron affinity decrease as you move from top to bottom. Explain in terms of the nucleus’s attraction for electrons. Be sure to discuss electron shielding and Coulomb’s law.

Answer 11

As you move down the column, the nucleus has a weaker attraction for outer electrons. This is because (1) e- shielding increases because you have more core electrons blocking the pull of the nucleus, and (2) e- are farther from the nucleus, making the attraction weaker, which is Coulomb’s law. A weaker attraction for outer electrons means that (1) outer e- are easier to remove (low IE) and there is not much attraction for new electrons (low e- affin.).

Question 12

Explain why nuclear charge increases as you move from left to right across the periodic table.

Answer 12

As you move from left to right, more protons are added to the nucleus. That means the nucleus has more positive charge.

Question 13

38. Explain why ionization energy and electron affinity increase as you move from left to right. Explain in terms of the nucleus’s attraction for electrons.

Answer 13

As you move from left to right, you add protons to the nucleus. That makes the positive nuclear charge stronger, which pulls on the electrons more tightly. This makes it harder to remove electrons (high IE) and easier to pull in new electrons (high e- affinity).

Question 14

Why do elements in the same group have similar properties?

Answer 14

They have the same outer energy level electron configuration.

Question 15

List four properties of alkali metals.

Answer 15

React vigorously with water to produce alkaline solutions and hydrogen gas, metallic properties, very reactive, soft, shiny but dull quickly when cut, only one electron in outer E level, lose the e- to become like a noble gas, become plasmas in the gaseous state at high temps

Question 16

Name two properties of alkali metals.

Answer 16

react with water to make alkaline (basic) solutions, one electron in their outer energy level, soft (can be cut with a knife), excellent conductors of electricity, etc.

Question 17

State the periodic law.

Answer 17

The physical and chemical properties of elements are periodic functions of their atomic numbers.

Question 18

What is another name for the main group elements?

Answer 18

______representative elements__________________

Question 19

What is a semiconductor?

Answer 19

A crystalline material with intermediate electrical conductivity

Question 20

Name the scientist who revised the periodic table to give us the table that we use today. How did he change Mendeleev’s table?

Answer 20

Mosely; Arranged it by atomic number instead.

Question 21

List the metalloids.

Answer 21

B, Si, Ge, As, Sb, Te

Question 22

Half the distance between two atoms bonded together

Answer 22

bond radius

Question 23

Metallic character ( increases / decreases ) as you move from left to right across the periodic table.

Answer 23

decreases

Question 24

High / Low ) ionization energy means that electrons are difficult to remove.

Answer 24

High

Question 25

( More negative / Less negative ) electron affinity means that electrons are more strongly attracted to the atom.

Answer 25

more negative

Question 26

9. List four properties of halogens.

Answer 26

Combine with metals to produce salts, most reactive nonmetals, seven electrons in outer E level, often acquire one e- in chemical reactions to form -1 ions

Question 27

Half the distance between two adjacent, nonbonded nuclei is called

Answer 27

van der waals radius

Question 28

8. List four properties of noble gases.

Answer 28

Not reactive, full outer energy level (stable octet), all gases, don’t bond with other elements, mostly inert, used in illuminated signs (Ne and Ar)

Question 29

List four properties of alkaline earth metals.

Answer 29

Harder, denser, stronger, and have higher melting points than alkali metals; reactive, but not as much as alkali metals; have two electrons in outer energy level

Question 30

35. What are salts formed from?

Answer 30

a halogen and a metal

Question 31

List four properties of metals.

Answer 31

Malleability (bendability), ductility (can be pulled into a wire), conduct heat, conduct electricity, luster (shiny)

Question 32

Explain what “electron shielding” is.

Answer 32

The reduction of the attractive force between a positively charged nucleus and its outermost electrons due to the cancellation of some of the positive charge by the negative charge of the other (core) electrons.