the periodic table

Question 1

How are elements ordered in the modern periodic table? ★

Answer 1

By their atomic/proton number.

Question 2

What are periods? What do elements in each period have in common? ★

Answer 2

Horizontal rows in the periodic table; elements in each row have the same number of shells.

Question 3

What are groups? What do elements in each group have in common? ★

Answer 3

Vertical columns in the periodic table; elements are grouped by the same number of electrons in their outermost shell.

Question 4

What are the majority of elements? ★

Answer 4

Metals.

Question 5

Where are metals and non-metals found on the periodic table? ★

Answer 5

● Metals: to the left side and towards the bottom of the Periodic Table.
● Non-metals: to the right side and towards the top of the Periodic Table.

Question 6

How were elements ordered in the old periodic table? Why was this a problem?

Answer 6

By their relative atomic masses; isotopes were a problem because of this.

Question 7

How did Newland order elements? ★

Answer 7

He ordered them in increasing atomic weight, where every 8^th element had similar properties and reacted similarly.

Question 8

How did Mendeleev order elements? What else did he do? ★

Answer 8

1. He ordered them in increasing relative atomic mass as protons not been discovered yet.
2. He switched the order of certain elements so they fitted patterns of properties of other elements in same group.
3. He left gaps for undiscovered elements (group 0 not been discovered) and predicted their properties using other elements - was correct.

Question 9

What enabled the order of the periodic table to be changed?

Answer 9

Knowledge of isotopes explained why the order based on atomic weight wasn’t always correct.

Question 10

What are the properties of metals? (6)

Answer 10

● Boiling/melting points: mostly high
● Conductivity: good, heat/electricity
● Appearance: lustrous
● Ductility: yes
● Malleability: yes
● Oxides: basic

Question 11

What do positive ions do?

Answer 11

They lose electrons.

Question 12

What do negative ions do?

Answer 12

They gain electrons.

Question 13

What is group 1 called? ★

Answer 13

Alkali metals.

Question 14

What is the chemical equation of alkali metals and water? What may you observe? ★

Answer 14

A. metal + Water —> Metal hydroxide + Hydrogen gas.
● They react vigorously with water fizzing and moving around on the surface of the water..

Question 15

What is the chemical equation of alkali metals and oxygen? What may you observe? ★

Answer 15

A. metals + Oxygen = White metal oxides.
● Colour of flames: Li = crimson-red, Na = yellow-orange, K = lilac.

Question 16

What is the chemical equation of alkali metals and green chlorine gas? What may you observe? ★

Answer 16

A. metal + Green chlorine gas = White metal chloride salts.

Question 17

Which elements in group 1 have a low density + float in water?

Answer 17

● Lithium (Li).
● Sodium (Na).
● Potassium (K).

Question 18

What are the trends reactivity in group 1? Why is this a trend? ★

Answer 18

Reactivity increases going down the group.
● This is due to the outer-shell electrons becoming further away from the nucleus as you go down the group.
● So the nuclear attraction weakens.
● There’s more shielding.
● The electron is easier to lose.

Question 19

What is group 0 called? ★

Answer 19

Noble gases.

Question 20

What is the reactivity of noble gases? Why? ★

Answer 20

They are unreactive and don’t easily form molecules; due to their atoms having a full outer shell of electrons, making them stable them stable.

Question 21

What are the properties in group 0? Why? ★

Answer 21

● Boiling point increases going down the group; There are stronger intermolecular attractions between electrons that need to be overcome.

Question 22

What is group 7 called?

Answer 22

Halogens.

Question 23

Are halogens metals or non-metals?

Answer 23

Non-metals.

Question 24

What do halogens form when reacting together?

Answer 24

Diatomic molecules (molecules with two atoms) joined together with a covalent bond.

Diatomic: consists of molecules made of pairs of atoms.

Question 25

What are the properties of halogens going down the periodic table?

Answer 25

● Relative molecule mass increases. ● Melting point increases. ● Boiling point increases.

Question 26

What are the trends in group 7?

Answer 26

● Reactivity decreases going down. ● This is due to the outer shell electrons becoming further away from the nucleus. ● So the nuclear attraction weakens. ● Electron is harder to gain.

Question 27

What are the appearances of Fluorine, Chlorine, Bromine and Iodine?

Answer 27

● Fluorine (F) = yellow gas. ● Chlorine (Cl) = green gas. ● Bromine (Br) = red-brown volatile liquid. ● Iodine (I) = dark grey solid/purple vapour.

Question 28

What is displacement?

Answer 28

1. When a more reactive element/metal displaces a less reactive element/metal in a reaction. 2. When a more reactive halogen displaces a less reactive halogen from an aqueous solution of its salt.

Question 29

What are the properties of transition metals?

Answer 29

● Hard and strong. ● High density. ● High melting points (except mercury). ● Less reactive than group 1 metals (e.g. with oxygen, chlorine, water). ● Good conductors.

Question 30

What ions do transition metals have? | [example included]

Answer 30

Ions with different charges noted by the roman numerals. | e.g. Fe (III) = Fe³⁺

Question 31

What compounds do transitions metals form? What can they be used as?

Answer 31

● Coloured compounds. ● Can be used as catalysts to speed up chemical reactions.

Question 32

What did Doberoëiner notice about the periodic table? ★ | [include example]

Answer 32

Elements with similar chemical properties often occurred in three’s (triads). | e.g, lithium, sodium, potassium all are heavily reactive in water.

Question 33

What are the properties of group 1? | state 5 facts.

Answer 33

● Soft metals (can be cut with a knife) ● Relatively low melting points ● Low density (Li, Na, K = less dense than water) ● React rapidly with oxygen, chlorine, water ● Form +1 ions e.g., Na+

Question 34

How do Group 1 elements react with non-metals? Why are these reactions similar for the different Group 1 elements?

Answer 34

They form ionic compounds which are soluble white solids which form colourless solutions – they all have one electron in their outer shell.

Question 35

What are the properties of non-metals? (6)

Answer 35

● Boiling/melting points: low ● Conductivity: don't (except graphite) ● Appearance: dull ● Ductility: no ● Malleability: brittle ● Oxides: acidic