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43 terms

NCEA level one chemistry

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Periodic Table
Chart with elements organized in regular cycles or groups
Element
Consists of atoms with the same number of protons.
Period
A horizontal row of elements on the PT- chemical properties change in a regular way
Group
Vertical column on PT- Elements have similar properties.
Metals
Left hand side of the PT- Malleable, ductile, solid, shiny, and conduct heat and electricity
Non-metals
Right hand side of the PT- Not metals, poor conductors of heat and electricity.
Halogens
Group 17 on the PT
Inert/Noble gases
Group 18 on the PT- Unreactive due to full outer shell
Atom
the smallest particle an element can be divided into- positively charged nucleus surrounded by electrons.
Molecule
Two or more atoms chemically joined
Compound
two or more different atom chemically joined
Proton
Positively charged particle found in the nucleus- also the atomic number
Neutron
neutral particle found in the nucleus- part on the mass
Electron
Negatively charged particle with very little mass- orbits the nucleus.
Nucleus
positively charged centre of an atom- made up on protons and neutrons and is the heavy part.
Mass number
Number of proton and electrons added together in the nucleus- what makes an element heavy
Atomic number
Number of protons in the nucleus- same as the number of electrons
Electron configuration
Order the electrons are arranged
Ionic compound
Made up of oppositely charged ions. Fill other shell of electrons are made by donating electrons. (metal-nonmetal)
Covalent compound
Compound made up of sharing electrons to get a full outer shell. (nonmetal-nonmetal)
Ion
charged atom or group of atoms
Isotope
The same element but different mass number. Same number of protons but different number of neutrons
Rate of reaction
how fast a reaction occurs
Collision theory
A reaction will only occur if particles collide with sufficient energy and at the right angle
Surface area and rate of reaction
surface area increases the number of collisions between particles per second so increases the rate of reaction.
Temperature and rate of reaction
Particles have more energy at higher temperatures. This increases number of collisions per second and the effectiveness of the collisions. Increases ROR
Concentration and rate of reaction
Increases number of particles so increases number of collisions per second. Increases the ROR
Catalyst and rate of reaction
Increased the effectiveness of collisions so it increases the ROR. They dont get used up in the reaction
Acid
pH less that 7. Produces H+ ions. Can neutralise a base
Base/alkali
pH greater that 7. produces OH- ions. Metal oxides or hydroxides are bases. Can neutralise acids
Lime water
Calcium hydroxide Ca(OH)2. Base- used to test for carbon dioxide- goes cloudy
pH scale
A way of measuring thow acidic or basic a substance is - less that 7= acid. 7=neutral. More than 7= base
Neutralisation
pH of 7. Neither acidic or basic. Acid and base cancel each other out.
Acid + Base (metal oxide/hydroxide)
= Salt + water
Acid + Carbonate
= Salt + Water + Carbon dioxide
Metal + Oxygen
= Metal Oxide
Acid + Metal
= Salt + Hydrogen
Decomposition
Decomposition reaction uses heat to break down a substance
Universal indicator
Changes colour depending on pH. Red > Orange > Yellow > Green > Blue > Purple
Litmus indicator
Changes colour depending on pH. Red=Acid. Green=Neutral. Purple=Base
Hydrogen test
Collect and burn gas. POP= hydrogen is present
Carbon dioxide test
Bubble gas through limewater. Goes cloudy if carbon dioxide is present
Oxygen test
Gas will relight a glowing splint if oxygen is present.