GCSE Chemistry- C1 Atomic structure and the Periodic table

charge of proton

+1

charge of neutron

neutral

charge of electron

negative

relative mass of proton

+1

relative mass of neutron

+1

relative mass of electron

1/1840 or very small

atomic number

the number of protons in an atom

atomic mass

The average mass of all the isotopes of an element

isotope

Atoms of the same element that have the same number of protons but a different numbers of neutrons

compound

A substance made up of atoms of two or more different elements chemically joined

Relative atomic mass

((%of isotope A x isotope A mass number)/100) + ((%of isotope B x isotope B mass number)/100)

Balancing Symbol Equations

always same number of atoms on both sides

equation balanced by numbers in front of formulas

H₂SO₄ + NaOH → Na₂SO₄ + 2H₂O

2 needed to balance hydrogen and oxygen

mixture

A combination of two or more substances that are not chemically combined

Separation techniques

filtration, crystallisation, simple distillation, chromatography

Chromatography

physical method of seperating a mixture of soluble substances based on each substances solubility

Simple distiliation

separation technique used to separate soluble substances based on their different boiling points

Filtration

a method us to separate a mixture of an insoluble substance from a solvent

insoluble

incapable of being dissolved

solvent

the substance in which the solute dissolves

soluble

capable of being dissolved

evaporational crystallisation

a separation technique used to separate a soluble substance from a solvent

John Dalton (1808)

Arranged in order of atomic weight, imagined the atom as a tiny sphere and each element was the same mass, proposed theory that atoms cannot be created or destroyed

Democritis' Discovery

Proposed that matter was composed of tiny indivisible particles called 'atomos' meaning uncuttable

J.J. Thompson "Plum Pudding" Model (1897)

Found that atoms contained smaller negatively charged particles called electrons, imagined an atom as a positively charged sphere with some negative bits around it. It is called the plum pudding model because the electrons drifted around like plum pieces in a plum pudding. Overall charge was neutral

Ernest Rutherford, Nuclear model (1911)

from Rutherford scattering experiment found that the positively charged part was very small, found that there was lots of space and negatives were small and random

Neils Bohr, electrons (1913)

found that electrons were not random, placed on shells/energy levels and very ordered

James Chadwick, Neutrons (1932)

Found that there was another subatomic particle called the neutron, the neutron has same mass as proton but no charge

What did the Rutherford scattering experiment find?

It found that lots of particles went straight through the gold foil, proving there was lots of empty space, small number of particles deflected because it repelled against a proton as positive+positive = repel, and some particles deflected because they hit an electron and went slightly sideways

What did the Rutherford scattering experiment prove?

It proved that the 'Plum Pudding' model was incorrect because it would've repelled back more often and it proved that there was lots of empty space in an atom.

Electronic structure

the arrangement of electrons in an atom

Number of electrons

= number of protons

mass of protons

= mass of neutrons

rules of electronic structure

only draw electrons, only draw shells/energy level (not nucleus), 2,8,8,2 pattern

New substance produced

chemical reaction

no new substance produced

physical reaction

involves transfers/sharing of electrons

chemical reaction

involes attraction between particles

physical reaction

boiling point, melting point and density

physical reaction

reaction with oxygen and water

chemical reaction

Properties of group 1 elements- alkali metals

shiny, reactive, soft, low melting point, low boiling temp, low density, less dense than water (buoyant), shiny surface which dulls when oxidised

number of group

The number of electrons in the outer shell

reactivity of group 1 metals

Increases down the group

group 1 metals with water

metal + water =hydrogen + metal hydroxide

group 1 metals with oxygen

metal + oxygen = metal oxide

group 1 metals with cholrine

metal + chlorine = metal chloride

diatomic element

an element that has two atoms in its particles and formula

diatomic elements

hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine

group 7 elements name

Halogens

what are group 7 metals

diatomic non-metals

group 7 halogens

Fluorine, Chlorine, Bromine, Iodine, Astatine

group 1 elements name

alkali metals

group 1 alkali metals

Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Caesium (Cs), Francium (Fr)

group 1 metals reactivity

more reactive down the periodic table

density of group 1 metals

low density

group 7 halogens boiling and melting points

increases down the group

group 0 elements name

noble gases

Group 7 properties

doesn't conduct electricity, coloured, poisonous, brittle and crumbly as solid, diatomic

reactivity in group 7

decreases as you go down the group

Chlorine physical properties at room temp

yellow gas, toxic

Bromine physical properties at room temp

orange/brown liquid

Iodine physical properties at room temp

purple solid

drawing ion rules

only outer shell, no need to draw nucleus, + or - on top right to show the charge, crosses for electrons that were already there, circles for electrons that is gained

displacement reaction

the least reactive element in a compound is replaced with a more reactive element to forma new compound

Group 0 elements

Helium, Neon, Argon, Krypton, Xenon, Radon

inert

unreactive

Uses for helium

party balloons

uses for neon

neon signs

uses for argon

double glazed windows

uses for krypton

car headlights

uses for xenon

halogen lamps

Uses for radon

radioactive research