1-53 (jack)

Question 1

what is a compound

Answer 1

a substance which contains two or more types of atom bonded together.

Question 2

what do mixtures contain

Answer 2

different elements or compounds that can be separated as they are not chemically bonded together

Question 3

how do u separate and insoluble solid from a mixture

Answer 3

filtration then dry and wash it to be pure

Question 4

how do u separate salt from a solution

Answer 4

evaporate the water to leave salt crystals

Question 5

how do u separate liquids from a mixture

Answer 5

use distillation to separate them based on their melting point

Question 6

isotope

Answer 6

Atoms of the same element that have different numbers of neutrons

Question 7

atomic number

Answer 7

number of protons

Question 8

mass number

Answer 8

number of protons and neutrons

Question 9

dalton

Answer 9

thought atoms were hard spheres and that elements had only one type of atom.

Question 10

jj thompson

Answer 10

discovered the electron and described atoms like ‘plum puddings’ with negative charges embedded in a cloud of positive charge.

Question 11

Geiger and Marsden

Answer 11

fired alpha particals at gold foil prooving atoms cant be solid

Question 12

Rutherford

Answer 12

proposed nuclear model with a positive atom as the nucleus with negative electrons orbiting

Question 13

what did neils bohr discover and in what year

Answer 13

1914 - energy levels

Question 14

what did james chadwick discover and in what year

Answer 14

1932 - neutron

Question 15

Before the discovery of protons, electrons and neutrons, what did scientists order elements by

Answer 15

atomic weight

Question 16

how did mendeleev arrange elements
(wordy answer)

Answer 16

in groups with similar properties predicting not yet discovered leaving gaps and occasionally changing the order of atomic weight

Question 17

The elements on the modern periodic table are arranged in order of

Answer 17

increasing atomic number

Question 18

what does the group number of an element say about the element

Answer 18

amount of electrons on outer shell

Question 19

What group are noble gases (2)

Answer 19

group 0 - unreactive as have full outer shell

Question 20

what happens to the boiling point as u go down group 0

Answer 20

increases

Question 21

what are the alkali metals

Answer 21

group 1

Question 22

charcteristics of group 1 (4)
reactivity (2)
general (2)

Answer 22

• very reactive
• reactivity increases as u go down group
• low density
• stored in oil to stop oxidization

Question 23

products of group 1 metals react with water (2)

Answer 23

alkaline solution of metal hydroxide and hydrogen gas

Question 24

what is group 7 called

Answer 24

halogens

Question 25

charcteristics of group 7 (3)

Answer 25

- non metals - diatomic molecules - melting/boiling point increases as you go down

Question 26

what happens to group 7 when it reacts with a metal (2)

Answer 26

form -1 ions in ionic compound

Question 27

halogens form ... when reacting with other non metals by...

Answer 27

covalent molecules and sharing electrons