S4 - Chemistry Test (1) Flashcards
What happens in a chemical reaction?
A new substance/substances are formed and the reactants turn to products
What is the rate of reaction?
The measure of how fast or slow a chemical reaction takes place/products are produced
What is a catalyst?
A substance which speeds up the rate of reaction but is chemically unchanged at the end of the reaction
What are the four factors which affect the rate of reaction?
- Concentration
- Particle size
- Temperature
- Use of a catalyst
What is the equation to find the average rate of reaction?
Av. rate = Change in product / Change in time
Name the seven diatomic elements
- Hydrogen
- Nitrogen
- Oxygen
- Fluorine
- Iodine
- Chlorine
- Bromine
What does the nucleus of an atom contain?
Protons and Neutrons
Where are the electrons in an atom?
In the shell/orbiting the nucleus
What is the mass of each particle that makes up an atom?
Proton = 1
Neutron = 1
Electron = 0
What is the charge of each particle in an atom?
Proton = positive
Neutron = none
Electron = negative
How do we tell what the atomic no. of an atom is?
The no. of protons it contains
How do we tell what the mass no. of an atom is?
The no. of protons + neutrons
Why are atoms neutral?
They contain the same no. of protons and electrons (+ & -)
How can we find the no. of neutrons in an atom
Mass no. - atomic no.
What is an isotope?
Atoms with the same atomic no. but different mass no.
What do elements in the same group have in common?
They have similar chemical properties
In nuclide notation, what do the no. on top and below the element represent?
On top: Mass no.
Below: Atomic no.
What are the 3 types of radiation?
- Alpha
- Beta
- Gamma
Why are atoms radioactive?
Their nuclei are unstable
What are the masses and the charges of the different types of radiation?
Alpha: 4, +2
Beta: 0, -1
Gamma: 0, 0
What is the penetrating power and the objects that stop the different types of radiations?
Alpha: Short, Paper
Beta: Medium, Aluminium
Gamma: Long, Lead or concrete
What is the half life of an atom?
The time taken for the number/mass or radioactive atoms in a substance to drop by half
What is the valency of an atom equal to?
The no. of electrons needed to form a full outer shell
What 2 types of molecules does ionic bonding occur between?
Non-metal and metal
What is a molecule?
A group of 2 or more atoms held together by covalent bonds
What does “Covalent Molecular” mean?
When strong covalent bonds hold atoms together but there are weak attractions between the molecules
What does “Covalent Network” mean?
When strong covalent bonds hold the whole structure together
Can covalent networks be dissolved?
No
What name is given to a molecule with…atoms?
- 2
- 3
- 4
- 5
- Linear
- Angular
- Pyramidal
- Tetrahedral
What is the definition of “valency”?
The no. of bonds that an atom of an element can form with other atoms
What no. do the following prefixes equate to?
- Mono
- Di
- Tetra
- Hexa
-Penta
- Tri
- 1
- 2
- 4
- 6
- 5
- 3
What are ions?
Particles with a positive or negative charge
What holds ionic compounds together?
The electrostatic force of attraction
What is an ionic lattice?
A regular arrangement of ions where each positive ion is surrounded by negative ions and each negative ion is surrounded by positive ones.
What are the properties of metals?
- Strong
- Conduct electricity and heat
- All solids except mercury
- Ductile
- Malleable
- Shiny (lustre)
What does it mean when electrons are delocalised and what type of bonding does it occur in?
- When the outer electrons are no longer attached to any single atom but are attracted to all positive cores in every direction
- Metallic bonding
Do ionic compounds conduct electricity?
Only when molten or in a solution as the ions are free to move
Can covalent compounds conduct?
What is the exception to this?
No
Graphite
What is the pH scale?
A continuous scale which gives a measure of how acidic or alkaline something is
What are the salt names for the following:
- Hydrochloric
- Nitric
- Sulphuric
- Carbonic
- Phosphoric
- Chloride
- Nitrate
- Sulphate
- Carbonate
- Phosphate
What are some common acids in chemistry?
What is their formula?
Hydrochloric acid - HCl
Sulfuric acid - H2SO4
Nitric acid - HNO3
Phosphoric acid - H3PO4
Ethanoic acid - CH3COOH
What are some common alkalis in chemistry?
What are their formulas?
Sodium hydroxide - NaOH
Potassium hydroxide - KOH
Calcium hydroxide - Ca(OH)2
What is an acid?
A substance with a higher concentration of hydrogen ions than hydroxide ions
What is an alkali?
A substance with a higher concentration or hydroxide ions than hydrogen ions
What is pH?
The measure of the hydrogen ion concentration of a substance
What solutions do soluble non-metal oxides form?
Acidic solutions
What solutions do soluble metal oxides form?
Alkaline solutions
What reacts in a neutralisation reaction?
An acid and a base
What is always formed in a neutralisation reaction?
A salt
What is a salt?
An ionic compound in which the hydrogen ion of the acid has been replaced with a metal ion
What is a base?
A material that can neutralise an acid
Name the different types of bases
- Metal oxides
- Metal hydroxides
- Metal carbonates
- Ammonia
What is produced when … (base) are used to neutralise an acid?
- Metal oxides
- Metal hydroxides
- Metal carbonates
- Metals
- Salt + water
- Salt + water
- Salt + water +Carbon dioxide
- Salt + Hydrogen
What are spectator ions?
Ions that appear unchanged on both sides of a reaction
