Chem year 10 for exam Flashcards
Periods
Across: number of electron shells
Groups
Down: number of valence electrons
Isotopes
Atoms of the same element, different number of neutrons in the nucleus
Group 1 elements
Alkali metals
Group 2 elements
Alkali earth metals
Group 17 elements
Halogens
Group 18 elements
Noble gases
Mass number
Number of protons and neutrons
Atomic number
Number of protons
Characteristics of metals
-Solid at room temperature
-Polished to produce a high shine/lustre
-Good conductors of electricity
-Malleable
-Can be made into a wire; ductile
-Usually melt at high temperatures (mercury is the exception)
Characteristics of non-metals
-Cannot be polished to produce a shine
-Brittle; shatter when hit
-Cannot be bent into shape; not malleable
-Usually, poor conductors of electricity and heat
-Usually melt at low temperatures
-Many are gases at room temperatures
The number of electrons per shell
2n^2
Flame test: ground state
Lowest energy state of an atom
Flame test: excited state
Highest energy state of an atom
Positively charged ions
Cations
Negatively charged ions
Anions
Electrostatic attraction
The attraction between two oppositely charged bodies
Covalent bond
A shared pair of electrons holding two atoms together
Activity series
Place elements in decreasing order of reactivity
Aqueous solution
Solution in which water is the solvent
Precipitate
Solid product of a chemical reaction that is insoluble in water
Relative atomic mass
A number that compares the mass of atoms to an agreed mass of carbon-12 isotope
Characteristics of alkali metals
All react strongly with water to form basic (alkaline) solutions, very reactive metals
Characteristics of alkali earth metals
Reactive metals
Characteristics of halogens
Brightly coloured elements, non-metals
Characteristics of noble gases
Inert, meaning they do not readily react with other substances, because they have a full valence shell
Characteristics of transition metal block
Block of metallic elements in the middle of the periodic table
Redox reactions
Chemical reactions involving oxidation and reduction; that is, electron transfer
OIL
Oxidation is Loss
RIG
Reduction is Gain
XY –> X + Y
Decomposition
X + Y –> XY
Combination
Acid + Base –> Salt + Water
Neutralisation
Methane + Oxygen –> Carbon Dioxide + Water
Combustion
Aqueous + Aqueous –> Solid + Aqueous
Precipitation (Double displacement)
A + BC –> AC + B
Single Displacement
Law of conservation of mass
Mass is neither created nor destroyed
Atomic radius =
Decrease left to right (have a bigger charge)
Increase top to bottom (More valence shells)
Isotope (nuclide) notation
Mass number Element
Atomic Number Element
Ion means
With full valence shell when written is eg. Na+
Valency
The valency is the number of electrons that each atom needs to gain, lose or share to fill its outer shell (for example, the valency of both chlorine and sodium is 1, whereas the valency of carbon is 4).
Electrovalency
The electrovalency of an element is equal to the charge on the ion (for example, the electrovalency for chlorine is –1 and sodium is +1).
Electrovalency is associated with
Ionic
Valency is associated with
Covalent
Is valency or electrovalency affected by charge
Electrovalency
The size of an electron compared to a proton is approximately
1800 times smaller
Energy is emitted from the sun as a result of
nuclear fusion
The atoms that came together to form the first starts were pulled together by
Gravity
A galaxy is
A group of stars