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Flashcards in DEFINITIONS SO FAR Deck (120)
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1

Atomic number

The number of protons in the nucleus of the atom

2

Mass (nucleon) number

The number of particles (protons and neutrons) in the nucleus

3

Isotopes

Atoms of the same element with the same number of neutrons but a different number of neutrons

4

Ions

An electrically charged particle formed by the loss or gain of one or more electrons from an atom or group of atoms

5

Relative isotopic mass

The mass of an atom of an isotope compared to 1/12th the mass of carbon 12

6

Relative atomic mass Ar

The weighted mean mass of an atom of an element compared to 1/12th the mass of carbon 12

7

Relative molecular mass Mr

The weighted mean mass of a molecule compared with 1/12th of the mass of an atom of carbon 12 (ONLY applies to simple covalent molecules e.g. O2 or CO2)

8

Relative formula mass

The weighted mean mass of a formula unit compared to 1/12th of the mass of an atom of carbon 12 (Can apply to ionic substances as they occur as giant lattices)

9

Molar gas volume

Volume per mole of gas.
Units= dm^3 mol^-1
At RTP= 24.0dm^3 mol^-1 approx.

10

Concentration (of a solution)

The amount of solute, in mol, dissolved per 1dm^3 (1000cm^3) of solution

11

Dilution

The process of decreasing the concentration of a solute in solution. Adding more solvent without adding more solute will reduce the concentration.

12

Compound

Atoms chemically joined

13

Molecule

2 or more atoms bonded with covalent bonds

14

Bond enthalpy

Average energy required to break one mole of that type of bond

15

Covalent bond

A shared pair of electrons

16

Ionic bond

Attraction (electrostatic) between oppositely charged ions

17

Element

Substance which contains only 1 type of atom

18

Orbital

A region that can be occupied by up to 2 electrons with opposite spins

19

Dative bond

Both of the shared electrons originate from the same species

20

Electronegativity

The ability of an atom to attract the bonding electrons in a covalent bond

21

Accuracy

How close to the true value a measurement is

22

Activation energy

Minimum energy required to start a reaction by breaking bonds in the reactants

23

Aim

The purpose of the investigation

24

Amount of substance

The quantity whose unit is mole. Amount of substance=counting atoms

25

Anhydrous

A substance containing no water molecules

26

Anion

Negatively charged ion

27

Anomalies

Data points that don't fit the overall trend in the data

28

Anomalous

Results that don't follow the general pattern of the data

29

Aqueous

A solution in which the solvent is water

30

Atom

Smallest object that retains properties of an element