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What is 1 + 3?
NCEA level one chemistry
Chart with elements organized in regular cycles or groups
Consists of atoms with the same number of protons.
A horizontal row of elements on the PT- chemical properties change in a regular way
Vertical column on PT- Elements have similar properties.
Left hand side of the PT- Malleable, ductile, solid, shiny, and conduct heat and electricity
Right hand side of the PT- Not metals, poor conductors of heat and electricity.
Group 17 on the PT
Group 18 on the PT- Unreactive due to full outer shell
the smallest particle an element can be divided into- positively charged nucleus surrounded by electrons.
Two or more atoms chemically joined
two or more different atom chemically joined
Positively charged particle found in the nucleus- also the atomic number
neutral particle found in the nucleus- part on the mass
Negatively charged particle with very little mass- orbits the nucleus.
positively charged centre of an atom- made up on protons and neutrons and is the heavy part.
Number of proton and electrons added together in the nucleus- what makes an element heavy
Number of protons in the nucleus- same as the number of electrons
Order the electrons are arranged
Made up of oppositely charged ions. Fill other shell of electrons are made by donating electrons. (metal-nonmetal)
Compound made up of sharing electrons to get a full outer shell. (nonmetal-nonmetal)
charged atom or group of atoms
The same element but different mass number. Same number of protons but different number of neutrons
Rate of reaction
how fast a reaction occurs
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
pH less that 7. Produces H+ ions. Can neutralise a base
pH greater that 7. produces OH- ions. Metal oxides or hydroxides are bases. Can neutralise acids
Calcium hydroxide Ca(OH)2. Base- used to test for carbon dioxide- goes cloudy
A way of measuring thow acidic or basic a substance is - less that 7= acid. 7=neutral. More than 7= base
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 reaction uses heat to break down a substance
Changes colour depending on pH. Red > Orange > Yellow > Green > Blue > Purple
Changes colour depending on pH. Red=Acid. Green=Neutral. Purple=Base
Collect and burn gas. POP= hydrogen is present
Carbon dioxide test
Bubble gas through limewater. Goes cloudy if carbon dioxide is present
Gas will relight a glowing splint if oxygen is present.