Atomic structure and the periodic table (1)

Question 1

atomic number-
atomic mass-

Answer 1

atomic number- bottom number, shows number of protons/electrons
atomic mass- top number, number of protons/electrons + neutrons

Question 2

Element-
Compound-
Mixture-

Answer 2

Element- only one type of atom
Compound- two or more atoms chemically bonded
Mixture- elements and/or compounds not chemically bonded

Question 3

What is an isotope

Answer 3

a different form of the same element with a different number of neutrons

Question 4

Relative atomic mass =

Answer 4

Relative atomic mass = sum of (isotope abundance x isotope atomic mass) / sum of all abundances of the isotopes

Question 5

Separation techniques:
chromatography-
filtration-
evaporation-
crystallisation-
distillation-

Answer 5

chromatography- separates dyes in ink using chromatography paper
filtration- separates an insoluble solid from a liquid using a funnel
evaporation- heating a liquid to remove it from a solution
crystallisation- the solid compound left after evaporation
distillation- separating liquids by evaporating, collecting and condensing them

Question 6

History of the atom:
John Dalton Billiard ball-
JJ Thompson Plum pudding-
Ernest Rutherford Nuclear model-
Bohr-
Rutherford-
Chadwick-

Answer 6

John Dalton Billiard ball- atoms where solid spheres
JJ Thompson Plum pudding- positively charged spheres with electrons in them
Ernest Rutherford Nuclear model- positive alpha particle scattering when electrons fired through gold foil showed that atom was mostly empty space with a small positive nucleus surrounded by electrons
Bohr- electrons orbit on fixed energy levels
Rutherford- discovered protons
Chadwick-discovered neutrons

Question 7

electron levels structure-

Answer 7

first shell- 2 electrons
second plus shell - 8 electrons

Question 8

Development of the periodic table:
structure in early 1800’s-
Dmitri Mendeleev-
Modern periodic table-

Answer 8

structure in the early 1800’s- elements arranged by atomic weight
Dmitri Mendeleev- in 1869 he reordered the table and left gaps for undiscovered elements with similar properties
Modern periodic table- organised by atomic number

Question 9

What are transition metals-
What are their properties-

non-metal properties-

Answer 9

metals between groups 2 and 3 in the periodic table
ductile, high melting/boiling point, malleable, conduct heat/electricity, shiny, sonorous

non-metal properties- dull looking, brittle, not solid at room temperature, lower density

Question 10

Group 0 elements-

Answer 10

noble gases (helium, neon, argon etc)
full outer shell of electrons so are unreactive
monoatomic gases- single atoms not bonded
boiling points increase going down the group
colourless gases at room temperature
non-flammable

Question 11

Group 1 elements-

reactions with water, chlorine, oxygen

Answer 11

alkali metals (sodium, lithium, potassium etc)
highly reactive, soft metals with one outer energy level electron
going down the group, reactivity increases and melting point lowers

water- produce hydrogen and metal hydroxides
chlorine- white metal chlorides
oxygen- forms metal oxides

Question 12

Group 7 elements-

Answer 12

halogens, non-metals with coloured vapours (flourine, chlorine, bromine etc) and seven outer shell electrons
Going down the group, reactivity decreases
halogens form ionic bonds with metals