topic 1 (atomic structure..)

Question 1

atom

Answer 1

an atom is a very small thing

Question 2

element

Answer 2

a single type of atom

Question 3

compound

Answer 3

2 or more elements that are chemically combined

Question 4

mixture

Answer 4

2 or more elements that are not chemically combined

Question 5

chromatography

Answer 5

involves separation of a solvent and solid (pen dots on a piece of paper)

Question 6

simple distillation

Answer 6

A method of separating mixtures based on differences in their volatilities in a boiling liquid mixture.

Question 7

fractional distillation

Answer 7

Fractional distillation is the separation of a mixture into its component parts, or fractions. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize.

Question 8

crystallisation

Answer 8

separate soluble salt from solution

Question 9

filtration

Answer 9

separating a liquid and a solid

Question 10

electron energy levels

Answer 10

a specific number of electrons go on each shell

2,8,8,16…

Question 11

alpha scattering experiment

Answer 11

In the experiment, positively charged alpha particles were fired at thin gold foil. Most alpha particles went straight through the foil. But a few were scattered in different directions. This evidence led Rutherford to suggest a new model for the atom, called the nuclear model

Question 12

the plum pudding model

Answer 12

this suggested the atom was a ball of positive charge with negative electrons embedded in it

Question 13

the nuclear model

Answer 13

niels Bohr explained electrons orbit the nucleus at fixed distances
the positive charge is due to protons
James Chadwick explains nucleus contains neutrons

Question 14

atomic number

Answer 14

is the number of protons/electrons in an atom

Question 15

mass number or atomic mass

Answer 15

is the number of protons plus neutrons in an atom

Question 16

periodic table

Answer 16

the early periodic table in 1800s were arranged by atomic mass
Mendeleev did take the elements properties into count
Mendeleev left gaps and predicted new elements

Question 17

properties of transition metals

Answer 17

high melting points.
high densities.
they form coloured compounds.
they (and their compounds) can act as catalysts.

Question 18

group 0 elements

Answer 18

The group 0 elements, the noble gases, are all unreactive non-metal gases. They show trends in their physical properties.
All group 0 noble gases have eight electrons in the full outer shell, except helium just has the two, but still a full shell! The melting point of group 0 noble gases increases down the group. The boiling point of group 0 noble gases increases down the group.

Question 19

group 1 elements

Answer 19

Alkali metals are grey solids with shiny silvery surfaces when freshly cut.

These surfaces turn dull when exposed to air.This is because alkali metals are very reactive.

They react rapidly with oxygen and water vapour in the air when exposed.

melting and boiling points decrease as you go down the group

Question 20

group 7 elements

Answer 20

The halogens have low melting points and low boiling points.

they are diatomic molecules (meaning they come in two’s)

they are highly reactive (mostly at the top)

increase in boiling point as you go down
used in sterilisation

Question 21

who discovered what?

Answer 21

jams Chadwick discovered the nucleus
jj Thomson discovered electrons (plum pudding model)
Ernest Rutherford -nuclear model