Chemisty flashcards

atoms

contained in the nucleus are the protons and neutrons. Moving around the nucleus are the electron shells they are negatively charged

Elements

made up of atoms with the same atomic number.

compounds

2 or more compounds chemically joined

Mixtures

In a mixture their are no chemical bonds, so the elements are easy to separate e.g air and salt water

John Dalton

Start of the 19th century discovered atoms were solid spheres

JJ Thompson

1897-plum pudding model.The atoms was a ball of charge with Electons scattered

Ernest Rutherford

1909-Mass concentrated at the centre ,The nucleus is charged, most atoms are empty space

Niels Bohr

around 1911-Electrons are in shells orbiting the nucleus

James Chadwick

1940-Discovered that their are neutrons in the nucleus

Mass of proton

1

Mass of electron

very small

mass of neutron

1

Relative atomic mass

The relative atomic mass of an element is the average mass of an atom of that element compared to one-twelfth the mass of an unbound carbon-12 atom.

Electronic structure

The arrangement of electrons in an atom.

Metals

Metals are strong , shiny and good conductors of electricity

Non metals

Non metals are brittle, dull and not always solid at room temp, poor conductors of heat and electricity

Noble gasses(group 1)

The noble gases (group 0 elements) include: helium, neon and argon. They are un-reactive as they have full outer shels, which makes them very stable.They are colourless at room temperature

Group 7-Halogens

Group 7 elements, known as halogens, are reactive non-metals that include fluorine, chlorine, bromine, iodine, and astatine.It is harder to gain the an extra electron because its outer shell its further away

Group 1-Alkali metals

Are soft, very reactive metals.They all have 1 electron in their outer shell, making them very reactive.They get bigger and it is easier to lose and electron.

transition metals

transition metals

Have expected metal properties, they speed up a reaction with out being used up themselves.Found in the middle of the periodic table

chemical bonds

hold molecules together and create temporary connections that are essential to life. Types of chemical bonds including covalent, ionic,

Ionic bonding

occurs between a metal and a non metal.The metal loses and electron to become positvly charged

covalent bonding

The sharing of a pair of electrons between atoms to gain a full outer shell.This occurs between non-metals only.

Metallic bonding

Occurs in only metals.Positive metal ions are surrounded by a sea of delocalised electrons.The ions are tightly packed and arranged in rows.

solid

Arranged in a regular pattern.The particles in a solid vibrate.Low amount of kinetic energy

Liquid

Particles randomly arranged, move around each other.The particles in a liquid have a greater amount o kinetic energy.They can flow

gas

Particles randomly arranged.Particles are able to move around very quickly.High amount of kinetic energy

Properties of ionic compounds

-High melting point

-High boiling point

-Cannot conduct electricity

When in molten solution they can conduct electricity

small molecules

• Small molecules have weak intermolecular forces.

• This means that small molecules have low melting and boiling points.

• Because of this, they are often liquids or gases at room temperature

• Cannot conduct electricity

Polymers

Long chain molecules that are made up of smaller units called monomers.

Atoms in a polymer chain are held together by strong covalent bonds

Giant covalent structures

• Graphite

• Graphene

• Dimond

Graphite structure/Properties

Made up of layers of carbon in hexagons, each carbon is bonded to 3 other carbons and one free delocalised electron.Graphite can conduct electricity

gasses in the atmostphere

• 78% nitrogen

• 21% oxygen

• 1% other

Greenhouse gasses

Carbon , water vapour , methane

climate change

long-term shifts in temperature affected by human activity

Carbon footprint

The amount of carbon dioxide and other green house gasses emitted over the full life cycle of a product service or event