Atomic Structure and the Periodic Table

Question 1

What determines the size of an atom?

Answer 1

Volume of electron’s orbits

Question 2

What is radius of an atom?

Answer 2

0.1 nano meters

Question 3

What is the charge of the nucleus and why?

Answer 3

Positive charge because protons

Question 4

What does the nucleus contain?

Answer 4

Contains protons and neutrons

Question 5

Where is almost the whole mass of atom is concentrated?

Answer 5

In nucleus

Question 6

What is no. of protons equal to?

Answer 6

no. of electrons

Question 7

What does the nuclear symbol of atom (i.e. what’s on the periodic table) tell you?

Answer 7

Its atomic number and mass number

Question 8

What a mass number?

Answer 8

Total number of protons and neutrons in atom

Question 9

What’s the atomic number?

Answer 9

Number of protons

Question 10

How do find the no. of neutrons?

Answer 10

Mass Number − Atomic Number

Question 11

What is the name given to substances that only contains atoms with same number of protons?

Answer 11

Elements

Question 12

Define isotopes

Answer 12

Different forms of same element, which have same no. of protons, but different no. of neutrons

Question 13

What is relative atomic mass?

Answer 13

Average mass of one atom of an element (including

isotopes)

Question 14

How are elements laid out in the periodic table?

Answer 14

In order of increasing atomic (proton) number

Question 15

Where are metals & non-metals on the periodic table?

Answer 15

Metals are on left and non-metals on right

Question 16

What does the group number tell you?

Answer 16

Number of electrons in outer shell

Exception Group 0 which has Helium (2 electrons)

Question 17

What do periods show you?

Answer 17

New period = another full shell of electrons

Question 18

What does having one electron on the outer shell do to an atom?

Answer 18

Makes them very reactive and gives similar properties

Question 19

Name 2 properties of Group 1 metals

Answer 19

All are soft and have low density

Question 20

As you go down Group 1…. (Name 3 things)

Answer 20

1. Increasing reactivity
2. Lower melting points
3. Lower boiling points
   (4. Higher relative atomic mass)

Question 21

Why does reactivity increase as you go down Group 1?

Answer 21

1. Outer shell electron is further away from nucleus, further down the group
2. ∴ attraction between nucleus and electron decreases
3. Outer electron is more easily lost

Question 22

What do alkali metals form with non-metals & why?

Answer 22

Ionic compounds with charge go +1 - don’t need much energy to remove 1 outer electron to form full outer shell

Question 23

What are ionic compounds formed from alkali metals and non-metals like?

Answer 23

Usually white solids that dissolve in water to form colourless solutions

Question 24

Name 3 observations that occur when alkali metals react with water

Answer 24

1. Metal travel quickly along surface of water
2. Lots of fizzing
3. Metal gets smaller
4. Universal indicator turns purple

Question 25

Why does universal indicator turn purple when alkali metals react with water?

Answer 25

Salts produced dissolve in water to produce alkaline solutions

Question 26

Name 2 properties of Group 7 elements

Answer 26

All Non-Metals with Coloured Vapours

Question 27

What structures do halogen compounds have?

Answer 27

Simple molecular (covalent) structures

Question 28

As you go down Group 7, halogens... (name 3 things)

Answer 28

1. Become less reactive 2. Have higher melting and boiling points 3. Have higher relative atomic masses

Question 29

Why does the reactivity decrease as you go down Group 7?

Answer 29

Harder to gain extra electron = outer shell's further from nucleus

Question 30

Name 2 properties of Group 0 elements

Answer 30

All Inert, Colourless Gases (at room temp)

Question 31

Why are noble gases non-flammable?

Answer 31

Bc they're inert

Question 32

What do noble gases exist as?

Answer 32

Exist as monatomic gases (single atoms not bonded to each other)

Question 33

As you go down group 0...

Answer 33

Boiling points of noble gases increase

Question 34

Why does the boiling point of noble gases increase as you go down the group (0)?

Answer 34

Bc there's increase in no. of electrons in each atom = greater intermolecular forces between them which need to be overcome

Question 35

Who developed the periodic table?

Answer 35

Dmitri Mendeleev

Question 36

What did Dmitri Mendeleev do to the periodic table?

Answer 36

Left gaps and predicted new elements

Question 37

What was the order of Mendeleev's periodic table?

Answer 37

Elements mainly in order of atomic mass but switched some to group that had other elements with similar properties

Question 38

What did the gaps in Mendeleev's periodic table ensure?

Answer 38

Elements with similar properties stayed in same groups

Question 39

Why were their gaps in Mendeleev's periodic table and what did this allow him to do?

Answer 39

Gaps indicated existence of undiscovered elements & allow him to predict what properties they may have

Question 40

Where are the transition metals located in the periodic table?

Answer 40

In centre of periodic table between group 2 and group 3

Question 41

Name 3 special properties of transition metals

Answer 41

1. Can have more than one ion 2. Compounds formed are colourful 3. Make good catalysts

Question 42

Why are compounds formed with transition metals colourful?

Answer 42

Transition metal ions = often coloured

Question 43

Give an example of a transition metal used as a catalyst in a named process

Answer 43

Iron catalyst used in Haber process

Question 44

Describe how properties of transition metals differ compared to the properties of group 1 metals (name 3 properties)

Answer 44

1. Have higher melting points (expect for mercury) + higher densities 2. Much less reactive 3. Are stronger and harder

Question 45

When alkali metals react with water, what do they release?

Answer 45

Hydrogen

Question 46

What do alkali metals form and what kind of solutions do they give when dissolved in water?

Answer 46

Form hydroxides that dissolve in water to give alkaline solutions

Question 47

Explain why fluorine is the most reactive element in Group 7

Answer 47

- Fewest energy levels in group 7 - Greatest attraction between nucleus and outer shell - ∴ fluorine can gain an electron in its outer shell more easily