FREE CHEMISTRY AND STUDY GAMES ABOUT AQA C2 KEY

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FREE CHEMISTRY AND STUDY GAMES ABOUT AQA C2 KEY

WORDS EXAM QUESTIONS

Qs and Ans Expert- Explanation

This Exam contains:

-Guarantee passing score -56 Questions and Answers -format set of multiple-choice -Expert- Explanation

Question 1: Delocalised Electron

Answer:

bonding electron that is no longer associated with any one particular atom.

Question 2: Relative Atomic Mass,Ar

Answer:

The average mass of the atoms of an element compared to carbon-12 (which is given the mass of exactly 12). The average mass must take into account the proportions of the naturally occurring isotopes of the element.

Question 3: Endothermic

Answer:

A reaction that takes in energy from the surroundings.

Question 4: Chromatography

Answer:

The process by which small amounts of dissolved substances are sepa by running a solvent along a material such as absorbent paper.

Question 5: Molecular Formula

Answer:

The chemical formula that shows the numbers of atoms in a particular molecule (e.g. C2H4).

Question 6: Covalent Bond

Answer:

The attraction between two atoms that share one, or more pairs of electrons.

Question 7: pH Scale

Answer:

A number which shows how strongly acidic or alkaline a solution is. Acids have a pH value of less than

• (pH 1 is strongly acidic). Alkalis have a pH value above 7 (pH 14 is strongly alkaline). A neutral liquid

has a pH value of 7.

Question 8: Mole

Answer:

The amount of substance in the relative atomic or formula mass of a substance in grams.

Question 9: Brine

Answer:

A solution of sodium chloride in water.

Question 10: Giant Covalent Structure

Answer:

a huge 3D network of covalently bonded atoms. (e.g. the giant lattice of carbon atoms in diamond or graphite.

Question 11: Reduction

Answer:

A reaction in which oxygen is removed (or electrons are gained).

Question 12: Compound

Answer:

A substance made when two or more elements are chemically bonded together.

Question 13: Alkali

Answer:

Its solution has a pH of more than 7.

Question 14: Monomers

Answer:

Small reactive molecules that react together in repeating sequences to form a very large molecule (a polymer).

Question 15: Activation Energy

Answer:

The minimum energy needed to start off a reaction.

Question 16: Atomic Number

Answer:

The number of protons (which equals the number of electrons) in an atom. It is sometimes called the proton number.

Question 17: Reversible Reaction

Answer:

A reaction in which the products can re-form the reactants.

Question 18: Molecular Ion Peak

Answer:

The peak on the mass spectrum of a substance which tells us the relative molecular mass of the substance. The peak is produced by the heaviest positive ion shown on the mass spectrum.

Question 19: Half Equation

Answer:

An equation that describes reduction (gain of electrons) or oxidation (loss of electrons), such as the reactions that take place at the electrodes during electrolysis.

Question 20: Electrolysis

Answer:

The breakdown of a substance containing ions by electricity.

Question 21: Ionic Bond

Answer:

the electrostatic force of attraction between positively and negatively charged ions.

Question 22: Polymerisation

Answer:

The reaction of monomers to make a polymer.

Question 23: Mass Spectrometer

Answer:

A machine that can be used to analyse small amounts of a substance to identify it and to find its relative molecular mass.

Question 24: Universal Indicator

Answer:

A mixture of indicators which can change through a range of colours depending on the pH of the solution. Its colour is matched to a pH number using a pH scale. It shows how strongly acidic or alkaline liquids and solutions are.

Question 25: Nanoscience

Answer:

The study of very tiny particles or structures between 1 and 100 nanometres in size- where 1 nanometre = 1x10-9metres

Question 26: Electrolyte

Answer:

A liquid, containing free-moving ions, that is broken down by electricity in the process of electrolysis.

Question 27: Ion

Answer:

a charged particle produced by the loss or gain of electrons.

Question 28: Catalyst

Answer:

A substance that speeds up a chemical reaction but remains chemically unchanged itself at the end of the reaction.