C2, The Periodic Table

Question 1

How were elements are arranged in 1800s and why

Answer 1

Via atomic mass because that’s all they could measure

Question 2

What was Mendeleev’s breakthrough

Answer 2

In 1869 Mendeleev took 50 elements and arranged them into a table of elements with various gaps

Question 3

Why were gaps left and what they indicate in Mendeleev’s periodic table

Answer 3

The gaps were left to make sure the elements with similar properties stayed in the same group

The gaps indicated the existence of unknown elements and allowed Mendeleev to predict their properties

Question 4

What does the atomic number determine

Answer 4

An elements position in the periodic table

Question 5

What determines chemical properties

Answer 5

The number of electrons in the outer most shell of an atom

Question 6

What is the group number equal to

Answer 6

The number of electrons in the outer most shell of all elements in that group

Question 7

Why are noble gases unreactive

Answer 7

Because they have stable electron arrangements because they have a full outer most shell

Question 8

What happens to melting points in the alkali metals (group1)

Answer 8

They decrease going down the group. The boiling points do the same

Question 9

What can all the alkali metals react with

Answer 9

They can react with water to produce hydrogen and alkaline solution containing the metal hydroxide

Question 10

How does the reactivity change in alkali metals

Answer 10

They increase when going down the group that’s why francium is so much more reactive than lithium

Question 11

How do melting and boiling points change in group 7 the halogens

Answer 11

Melting and boiling points increase going down the group however they already have relatively low melting and boiling points in comparison

Question 12

What type of ion does halogens form

Answer 12

They form irons with a -1 charge in the ionic compounds with metals

They also form covalent compounds by sharing electrons with other non-metals

Question 13

How does the reactivity of halogens change

Answer 13

They decrease whilst going down the group

Question 14

What is electrostatic attraction

Answer 14

The attraction between electrons in the outer most shell and the nucleus

Question 15

What does electrostatic attraction depend on

Answer 15

1) The distance between the valence shell and nucleus
2) The number of occupied in shells on an electron which provide a shielding affect
3) The size of the positive charge on the nucleus

Question 16

How did the size of atoms change regarding the amount of electrons

Answer 16

Larger atoms lose electrons more easily going down the group whereas they gain electrons less easily going down the group

Question 17

Features of transition elements

Answer 17

They have much higher melting points and density and they are also stronger and harder but are much less reactive

Question 18

What ions can transition metals form

Answer 18

They conform are you into different charges and they are very important industrial catalysts