Chemistry

Question 1

Define an element

Answer 1

Substances made from only one type of atom.

Question 2

Define a compound

Answer 2

Substances made from two or more types of atoms bonded together.

Question 3

Define a mixture

Answer 3

Groups of atoms, elements and compounds that are mixed but not bonded.

Question 4

Define an ion

Answer 4

Charged particle formed when an atom has lost or gained electrons.

Question 5

Define an isotopes

Answer 5

Atoms of the same element (same number of protons) with a different number of neutrons.

Question 6

Name the process to separate two liquids

Answer 6

Fractional Distillation

Question 7

Name the process to separate an insoluble solid from a liquid

Answer 7

Filtration.

Question 8

Name the process to separate a soluble solid from a liquid

Answer 8

Crystallisation.

Question 9

Describe the contribution of Dalton to develop the periodic table

Answer 9

Ordered elements based on their atomic mass

Question 10

Describe the contribution of Newlands to develop the periodic table

Answer 10

Kept atomic mass. Discovered a repeating pattern every 8th element.

Question 11

Describe the contribution of Mendeleev to develop the periodic table

Answer 11

Switched positions of elements that did not fit patterns. Left gaps for undiscovered elements.

Question 12

Describe the contribution of Moseley to develop the periodic table

Answer 12

Ordered elements based on the number of protons they had.

Question 13

Give the properties of alkali metals

Answer 13

Very reactive, low melting/boiling points, react vigorously with water and halogens

Question 14

Give the properties of the halogens

Answer 14

Low melting/boiling points, poor conductors of heat/electricity, toxic, react with alkali metals.

Question 15

Give the properties of noble gases

Answer 15

Very unreactive, stable, full outer shell, exist as single atoms.

Question 16

Identify the pattern of reactivity in group 1 (Alkali metals)

Answer 16

The Alkali metals become more reactive as you go down the periodic table.

Question 17

Identify the pattern of reactivity in group 7 (Halogens)

Answer 17

The Halogens become less reactive as you go down the periodic table.

Question 18

Define a displacement reaction

Answer 18

When a more reactive element takes the place of a less reactive element in a compound.

Question 19

Describe what happens in ionic bonding.

Answer 19

Electrons are lost or gained.

Question 20

Describe what happens during covalent bonding.

Answer 20

Electrons are shared.

Question 21

List the properties of solids.

Answer 21

Fixed shape, fixed volume, cannot be compressed, particles arranged in rows, particles vibrate in fixed positions.

Question 22

Describe the properties of ionic compounds.

Answer 22

High melting and boiling points, conducts electricity when molten/dissolved, brittle

Question 23

Give the structure that ionic compounds form

Answer 23

Giant lattices.

Question 24

Explain why ionic compounds have high melting/boiling points.

Answer 24

Strong electrostatic forces between oppositely charged ions, lots of energy

Question 25

Explain why diamond is hard and strong.

Answer 25

Forms 4 covalent bonds per atom. This is the max number of bonds. Lots of energy required to break them.

Question 26

Explain why graphite can conduct electricity.

Answer 26

Only forms 3 bonds per atom. This means there is 1 spare electron that can conduct electricity.

Question 27

Describe the structure of metals.

Answer 27

Positive metal ions. A sea of delocalised electrons. Strong electrostatic forces between them.

Question 28

group 1

Answer 28

alkali metals

Question 29

group 2

Answer 29

earth metals

Question 30

in the middle of the periodic table

Answer 30

transition metals

Question 31

group 7

Answer 31

halogens

Question 32

john dalton

Answer 32

solid sphere model 1st model ( big sphere ball crushing town of dolls!!)

Question 33

JJ Thomson

Answer 33

Plum pudding model 2nd model (JJ from obx shooting plum pudding to bits with thomson gun)

Question 34

Ernest Rutherford

Answer 34

Nuclear model 3rd model ( Ruth driving in a ford giving nukews to people in a nest)

Question 35

Neils bohr

Answer 35

Planetrey model ( Neil from young ones being a bohr and talking about planets as he spins around them)

Question 36

In an element , which number is the atomic number (ALSO THE NUMBER OF PROTONS)!!

Answer 36

THE SMALLER ONE!!! THE MASS NUMBER IS THE BIGGER ONE!!!! atomic number is usually at the top or the left. mass number is usually at the bottom or at the top right.

Question 37

how do you find out the number of neutrons?

Answer 37

Atomic mass - atomic number

Question 38

how do you work out the mass number of. an element

Answer 38

add protons and neutrons together

Question 39

What is the mobile phase and the stationary phase in cryptography

Answer 39

Stationary: paper Mobile phase : solvent that moves through the paper

Question 40

Equation that links distance moved by solvent distance moved by solute and rf value

Answer 40

Rf = distance moved by substance/ distance moved by solvent

Question 41

How to calculate rf value for cormorant

Answer 41

Measure solvent front from bottom of paper NOT THE LINE and divide it by the distance the pigment has moved up the page FROM TTHE BITTOM OF THE PAGE!

Question 42

John dalton

Answer 42

Ordered elements according to atomic mass

Question 43

John newlands

Answer 43

Discovered a repeating pattern every 8th element

Question 44

Dmitri Mendeleev

Answer 44

Switched position of elements that didn’t fit the pattern left gaps for undiscovered elements

Question 45

Henry Mosley

Answer 45

Ordered elements by proton number

Question 46

How to find groupo number quickly

Answer 46

amount of electrons in outer shell of that element is what group it is in

Question 47

in cromotography what is the substance and the solvent

Answer 47

substance - ink solvent - water or propanone

Question 48

why use pencil in cromotography

Answer 48

doesnt dissolve in solvent like ink does.