topic 1 atomic structure

Question 1

Substance a contains only one type of atoms and does not conduct electricity

Answer 1

Non-metallic element

Question 2

Give meaning meaning meaning of isotopes answer in terms of subatomic particles

Answer 2

atoms with the same number of protons but with different numbers of neutrons

Question 3

which scientist first suggested that electrons orbit the nucleus at specific distances?

Answer 3

bohr

Question 4

describe three differences between nuclear model of atom and plum pudding model

Answer 4

nuclear-empty space, positive charge in the nucleus, mass is concentrated in nucleus, the electrons and the nucleus are separated

Question 5

describe the change bohr made to the nuclear model

Answer 5

Electrons orbit the nucleus

Electrons are at specific distances from the nucleus

Question 6

which gas is produced when group one elements react with water?

Answer 6

Hydrogen

Question 7

explain why reactivity of elements change going down group one

Answer 7

because the outer electron is further from the nucleus

So there is less attraction between the nucleus and the outer electrons so the atom loses an electron more easily

Question 8

two statements of the properties of most transition metals

Answer 8

The form ions with different charges, they have high melting points

Question 9

explain why oxygen is described being reduced in the reaction between sodium and oxygen

Answer 9

oxygen gains electrons

Question 10

Explain my ammonia has a low melting point

Answer 10

has small molecules

Has weak inter molecular forces

Little energy needed to overcome the intermolecular forces

Question 11

Describe and explain fractional distillation

Answer 11

A technique for separating mixtures of liquids.

It works when liquids have a different boiling point

Question 12

What is an atom?

Answer 12

The smallest part of an element that can exist

Question 13

What is an element?

Answer 13

An element is a substance of only one type of atom

Question 14

describe and explain simple distillation

Answer 14

simple distillation is used to separate liquid from a solution – the liquid boils off and condenses in the condenser. The firm monitor will read the boiling point of a pure liquid. Contrary to evaporation, we get to keep the liquid. 

Question 15

Describe and explain crystallisation/evaporation

Answer 15

evaporation is a technique for separation of a solid dissolved in a solvent from a solvent. The solution is heated until all the solvent evaporates: the solid stays in the vessel.

Crystallisation is similar, but we only remove some of the solvent by evaporation to form a saturated solution. Then we call down the solution. As we do it, the solid starts to crystallise, as it becomes less soluble at lower temperatures. The crystals can be collected and separated from the solvent via filtration.

Question 16

Describe and explain fractional distillation

Answer 16

fractional distillation is a technique for separation of mixture of liquids. It works one liquids have different boiling poles. The apparatus is similar to one of the simple distillation operators, with additional fractionating colonplace on the top of the heated flask.

The fraction in column contains glass speeds.

It helps to separate the compounds.

In industry, mixtures are repeatedly condensed and vaporise. The column is hot at the bottom and colder the top. Liquids will condense at different heights of the column.

Question 17

describe and explain filtration

Answer 17

Filtration is used to separate and insoluble solid is suspended in a liquid. The insatiable solid gets caught in the filter paper, because the particles are too big to fit through the holes in the paper. The filtrate is the substance that comes through the filter paper.

Question 18

Describe and explain chromatography

Answer 18

chromatography used to separate a mixture of substances dissolved in a solvent. In paper chromatography replace a piece of paper with a spark containing mixture in a beaker with some solvent. The bottom of the paper has been contact with the solvent. The solvent level will slowly start rise, this separating thespot into few spots

Question 19

what is a separating funnel?

Answer 19

A separating funnel is an apparatus for separating immiscible liquids .Two immiscible liquids of different densities or form two distinct layers in the separatory funnel we can run off the bottom layer to separate vessel 

Question 20

State the colours are flames observed when lithium, sodium and potassium burning in oxygen

Answer 20

crimson-red Li
yellow-orange Na
lilac K

Question 21

describe the properties of noble gases. Discuss the trends in properties down the group.

Answer 21

Non-metal, gases, low boiling points, unreactive
boiling point increases down the group as the atoms get heavier