YR 9 - The Periodic Table

Question 1

how are elements ordered in the modern periodic table?

Answer 1

elements are ordered by their atomic number/proton number in the modern periodic table.

Question 2

what are groups?

Answer 2

• groups are the vertical columns in the periodic table.
• elements in each group have the same number of electrons in their outer shell.

Question 3

what are periods?

Answer 3

• periods are the horizontal rows in the periodic table.
• elements in each row have the same amount of shells.

Question 4

what are the majority of elements?

Answer 4

the majority of elements are metals.

Question 5

where are metals and non-metals located?

Answer 5

• metals are found to the left and bottom of the periodic table.
• non-metals are found to the right and top of the periodic table.

Question 6

how were elements ordered in the old periodic table and why was this a problem?

Answer 6

• elements were ordered by their atomic weight in the old periodic table.
• isotopes were a problem using this order causing the periodic table to be rearranged in order of atomic numbers.

Question 7

how did John Newland order the elements in the periodic table?

Answer 7

he ordered elements where every 8th element reacted similarly - Newland’s octaves.

Question 8

how did Dmitri Mendeleev order the elements in the periodic table?

Answer 8

• he ordered elements in increasing mass.
• he switched the order so that the elements fitted patterns of their physical and chemical properties.
• he left gaps for undiscovered elements.

Question 9

what helped prove that ordering in atomic weight was insufficient?

Answer 9

knowledge of isotopes made it possible to explain why the order based on atomic weight was incorrect.

Question 10

what are metals?

Answer 10

• good conductors of heat and electricity
• have delocalised electrons that move and carry charged
• ductile (can be drawn into wires)
• malleable (able to be bent/shaped) 

Question 11

what are positive ions?

Answer 11

elements that react to form positive ions are metals - they lose electrons from their outer shells.

Question 12

what are negative ions?

Answer 12

elements that form negative ions are non-metals - they gain electrons onto their outer shell.

Question 13

what are group 1 named?

Answer 13

group 1 are named the alkali metals.

Question 14

how do group 1 metals react with water and what do they produce?

Answer 14

• group 1 metals are highly reactive with water.
• they produce metal hydroxide with hydrogen gas.

metal + water —> metal hydroxide + hydrogen

Question 15

what do group 1 metals produce when reacting with oxygen?

Answer 15

group 1 metals react with oxygen to produce white metal oxides

metal + oxygen —> metal oxide

Question 16

what do group 1 metals produce when texting with green chlorine gas?

Answer 16

group 1 metals react to produce a white metal chloride salt.

Question 17

which metals in group 1 have a low density and float in water?

Answer 17

lithium (Li), sodium (Na) and potassium (K) all have low density and float in water.

Question 18

what is the pattern of reactivity in group 1 and what is the reason for it?

Answer 18

in group 1, the reactivity of the elements increases going down the group.

• this is because as you go down the group:
— the outer shell electrons become further away from the nucleus
— the nuclear attraction from the positive nucleus to the negative electron decrease
— there is more shielding
— the electron is easier to be removed/lost