C3 Flashcards
Define an isotope
atoms of the same element which have the same proton number but a different nucleon number
Define nucleon number
(mass number) as the total number of protons and neutrons in the nucleus of an atom
Define proton number
(atomic number) as the number of protons in the nucleus of an atom
Define the term solvent
It is the substance in which the solute is dissolved
Define the term solute
a solid that is dissolved into a liquid
Define the term solution
The mixture formed when a solute dissolves in a solvent
Define the term concentration
the amount of a substance in a defined space.
Name the 3 elements in an atom
Central nucleus (containing protons, neutrons)
Shells of electrons
Define an element
A substance that cannot be further broken down by any chemical reaction.
(Each element has a unique number of protons in its atom)
Define mixture
A mixture is made from different substances that are not chemically joined.
Define compound
A compound is formed when two or more atoms join together chemically, with covalent or ionic bonds
Describe the difference between a mixture and a compound {2}
- Mixture is made from different substances but not chemically joined together.
-Compound is made from different substances when they are chemically joined together
Describe 4 differences between metals and non-metals [4]
(7 are listed on the other side)
Metals- Shiny, high melting points, good conductors of electricity and heat, high density, malleable
Non-metals- Dull, low melting points, poor conductors of electricity and heat, low density, Brittle
Describe the lattice structure of ionic compounds
A regular arrangement of alternating positive
and negative ions,
ex. the sodium chloride structure
How do you identify physical changes from chemical changes?
Physical changes are to do with the state of matter. The substance will be a different shape or size at the end but no new substances are formed.
Chemical changes produce a new substance and either absorbs or releases energy during the reaction. Chemical reactions are on a nuclear level
Give 2 examples of physical changes [2]
boiling water, melting ice, breaking a bottle, crumbling paper.
Give 2 examples of chemical changes [2]
burning wood, dissolving salt in water, and digesting food.
State the different forms of carbon [2]
Diamond, graphite
Describe the giant covalent structure of diamond
Every carbon atom is bonded to 4 other carbon atoms with strong covalent bonds
Describe the giant covalent structure of graphite
Each carbon is bonded by 3 strong covalent bonds to make a giant structure consisting of layers of hexagons
State the relative mass and charge for
- protons [2]
-neutrons [2]
-electrons [2]
Protons- mass= 1 charge= +1
neutrons- mass=1 charge= 0
electrons- 1/1840 (saying nothing or negligible is accepted) charge= -1
State 2 uses for radioactive isotopes
- Used in medicine (sterilise equipment or treat cancer tumours)
- Used in industry (to detect leaks in pipes)
Why do isotopes have the same chemical properties?
Because they have the same number of electrons in their outer shells
Describe the formation of an anion
(state which atoms become anions)
If an atom gains electrons, there are more electrons than protons so, negative ions are formed
(Non-metals gain electrons to become anions)
What is the name of a negatively charged ion?
Anion
What is the name of a positively charged ion?
Cation
Describe the formation of a cation
(State which atoms become cations)
If an atom loses electrons, there are more protons than electrons, so a positive ion is formed
(Metals lose electrons to become cations)