Chemistry 8 Flashcards
1st Atomic theory
Solid sphere 460-370BCE, Democrites
2nd Atomic theory
Plum pudding model 1904, J.J. Thompson
3rd Atomic theory
Nuclear model 1911, Rutherford (gold foil test)
4th Atomic theory
Planetary model 1913, Bohr
Current atomic theory
Quantum model 1926-now, Schrödinger
Groups 1, 2 and 3 of the periodic table…
give away electrons
Groups 5, 6 and 7 of the periodic table…
take electrons
Group 4 of the periodic table…
shares electrons
Noble gases are group…
8
Are noble gases reactive?
no
Halogens are group…
7
What happens as you move up the group of halogens?
They get more reactive
What happens as you move up group 1?
They get less reactive
Metals between groups 2 and 3 are…
transition metals
Groups 1, 2 and 3 have a ___ charge as ions
positive
Groups 5, 6 and 7 have a ___ charge as ions
negative
What is ionic bonding
Bonding between a metal and non-metal
What is covalent bonding
Bonding between two non-metals
Name 3 acids
HCl (Hydrochloric acid), HNO3 (Nitric Acid), H2SO4 (Sulfuric acid)
Name 3 alkalis
Ca(OH)2 (limewater), NaOH (Sodium Hydroxide), Mg(OH)2 (Magnesium hydroxide)
Hydrochloric acid makes
chloride salt
Nitric acid makes
nitrate salt
Sulfuric acid makes
Sulfate salt
Acid + Alkali →
Salt + Water
Acid + metal oxide →
Salt + Water
Acid + metal carbonate →
Salt + Water + carbon dioxide
Acid + metal hydroxide →
Salt + Water
Acid + metal →
Salt + Hydrogen
How do you test for hydrogen?
Squeaky pop test
How do you test for carbon dioxide?
Limewater goes cloudy
Endothermic
a reaction in which heat is absorbed
Exothermic
a chemical reaction that produces heat
What is the chemical reaction used in a cold pack?
NH4NO3 (s) + water = NH4NO3 (aq)
What is the chemical reaction used in a heat pack
CaCl2 (s) + water = CaCl2 (aq)
Atomic number
number of protons
Mass number
number of protons and neutrons
Ion
An atom or small group of atoms that has an electrical charge because it has gained or lost an electron
Acid
Substance that releases hydrogen ions into liquid solutions
Alkali
A base dissolved in water that that releases OH ions into liquid solutions
Salt
A neutral substance
Neutralisation
The reaction between an acid and a base, which produces a salt and water
Chemical change
A change where a new substance is formed, bonds between atoms are broken, new bonds are formed, and atoms are rearranged
Physical change
A change in the appearance of a substance without a new substance being formed
Chemical bond
The join between two atoms that keep them connected
Respiration
A chemical process in which energy is produced in the body from food using oxygen
How do ionic bonds happen?
metal gives electrons and non-metal takes electrons
How do covalent bonds happen?
They share electrons so that one can complete it’s outer shell
