Unit 3: How do we use matter?

Question 1

What are the three parts of an atom?

Answer 1

Proton, neutron electron

Question 2

Define an electron

Answer 2

An electron is a subatomic particle with a negative charge, located in shells outside the nucleus.

Question 3

Define an ion

Answer 3

An ion is an atom or group of atoms with an unbalanced number of charges due to gaining or losing an electron.

Question 4

Define a cation

Answer 4

A cation is a positively charged ion due to an atom losing an electron.

Question 5

Define an anion

Answer 5

An anion is a negatively charged ion due to an atom gaining an electron.

Question 6

What is atomic mass?

Answer 6

Atomic mass refers to the mass of an atom, found by adding the number of protons and neutrons

Question 7

What is atomic number?

Answer 7

Atomic number refers to the number of protons an element of an element has. No two atoms of an element have the same atomic number.

Question 8

What are the three categories of the periodic table?

Answer 8

Metals, non-metals, and metalloids

Question 9

What are the physical properties of metals?

Answer 9

• Shiny
• High melting point
• Good conductors of heat and electricity
• High density
• Malleable
• Ductile
• Sonorous (ring when struck)
• Tend to lose electrons to form cations

Question 10

What are the chemical properties of metals?

Answer 10

Metals form oxides which are acidic. Metals are more likely to corrode and more likely to react with acids or water.

Question 11

What are the physical properties of non-metals?

Answer 11

• Dull
• Low melting point
• Low density
• Brittle
• Non-ductile
• Poor conductors of heat and electricity
• Tend to gain electrons to form anions

Question 12

What are the chemical properties of non-metals?

Answer 12

Non-metals form oxides that are acidic.

Question 13

What are group 1 elements called?

Answer 13

Alkali metals

Question 14

Which group in the periodic table is the most reactive?

Answer 14

Alkali metals are the most reactive group

Question 15

How many valence electrons do alkali metals have?

Answer 15

1 valence electron

Question 16

Why are alkali metals stored under oil?

Answer 16

Alkali metals react very quickly with water and air and storing them underwater prevents this reaction.

Question 17

Why does reactivity increase down group 1?

Answer 17

As you go down group 1 elements, the atom gets bigger. The bigger the atom the further away the valence electrons are. As a result, the attraction between the nucleus and the valence electrons is weaker, making the atom lose electrons more easily.

Question 18

How does metal react with water?

Answer 18

Metal reacts with water to form metal hydroxide and hydrogen.

Question 19

What are the properties of alkali metals?

Answer 19

• Highly reactive
• Low density
• Soft
• Low melting point

Question 20

How do alkali metals react with oxygen?

Answer 20

Alkali metals react with oxygen to form oxides which have a fuller appearance and lower reactivity than the pure metal.

Question 21

How do alkali metals react with water?

Answer 21

Alkali metals react vigorously with water. Oxides and metal hydroxides are produced, and hydrogen gas is released.

Question 22

What are the trends seen moving down group 1 of the periodic table?

Answer 22

Increasing atomic radius, increasing reactivity, decreasing electronegativity and decreasing melting and boiling point.

Question 23

Where are alkaline earth metals found in the periodic table?

Answer 23

Group 2 of the periodic table

Question 24

What are the properties of alkaline earth metals?

Answer 24

• Alkaline earth metals are found in group 2 of the periodic table
• They have 2 electrons in their outermost shell – 2 valence electrons
• Reactivity and density increase down the group
• Melting and boiling point decreases down the group
• Somewhat reactive at standard temperature and pressure
• Lose 2 electrons when they react to form a cation (positive ion) with 2+ charge
• Metals become softer down the group
• They are found in the s-block

Question 25

What block are alkali metals found in?

Answer 25

s-block

Question 26

What block are alkaline earth metals found in?

Answer 26

s-block

Question 27

How many valence electrons do alkaline earth metals have?

Answer 27

2 valence electrons

Question 28

What two properties increase as you go down the alkaline earth metals group?

Answer 28

Reactivity and density

Question 29

What two properties decrease as you go down the alkaline earth metals group?

Answer 29

Melting and boiling point

Question 30

What group are transition metals found in?

Answer 30

Group 3 to 12

Question 31

What block are transition metals found in?

Answer 31

d-block

Question 32

What group of elements can be used as a catalyst?

Answer 32

Transition metals

Question 33

Which group are halogens found in?

Answer 33

Group 17

Question 34

How many valence electrons do halogens have?

Answer 34

Seven valence electrons

Question 35

What properties increase down the halogens group?

Answer 35

Atomic radium, melting and boiling point

Question 36

What properties decrease down the halogen group?

Answer 36

Electronegativity and reactivity

Question 37

Define inert

Answer 37

Chemically unreactive

Question 38

What group are noble gases in?

Answer 38

Group 18 of the periodic table

Question 39

Why are noble gases inert?

Answer 39

They have a full outer shell

Question 40

What are the properties of non-metals?

Answer 40

Dull, low melting point, low density, brittle, non-ductile, poor conductors of heat and electricity and tend to gain electrons to form anions.

Question 41

What are the properties of metalloids?

Answer 41

They have properties of both metals and non-metals, they are solids that can be shiny or dull, they are better conductors of heat and electricity than non-metals, but not as good as metals and they are ductile and malleable.

Question 42

Calculate the relative formula mass of carbon sulfate CaSO4 (Ca: 40 | S = 32 | O = 16)

Answer 42

(40 x 1) + (32 x 1) + (16 x 4) = 40 + 32 + 64 = 136

Question 43

Describe the pattern of first ionization energy within a group?

Answer 43

As you go down a group, atomic number increases, and the outermost electron shell is at an increasingly higher energy level. Each successive energy level is further away from the nucleus so atomic radius also increases, and the level of shielding between the valence electrons and the nucleus increases down a group. As a result of increasing level of shielding, the strength of the bonds holding the valence electrons to the nucleus decreases. The decrease in the first ionization energy results in an increase in reactivity. The weaker the hold of the positively charged nucleus on the negative electrons, the easier for the atoms to lose its electrons and the more reactive it is.

Question 44

What is effective nuclear charge?

Answer 44

The positivity of the nucleus

Question 45

Describe the pattern of the first ionization energy across each period?

Answer 45

As you move across each period, the level of shielding remains constant. The number of valence electrons increases by one for each element and is placed in an orbital with a similar energy level. However, the effective nuclear charge increases for each element because of the increase in the number of protons. With an increasing effective nuclear charge and a constant energy level, the hold between the valence electrons and the nucleus increases across a period, and the first ionization energy decreases. As a result, it is harder for atoms to lose electrons and reactivity decreases. The only two exceptions are aluminum and sulfur.

Question 46

Outline the trends in group 17 of the periodic table

Answer 46

- State of matter changes as you go down the group - Shielding increases - Number of full inner electron shells increases - Reactivity decreases down the group - Effective nuclear charge decreases