Year 8 Cycle 3 Science Flashcards
(41 cards)
A mutation is a change in the DNA sequence of a gene.
Mutations can lead to genetic conditions like cancer or they can lead to adaptations
Offspring inherit one version of each gene (allele) from each parent
The combination of inherited alleles leads to variation between individuals,
Static electricity is the build up of charge on an object due to the transfer of electrons
Opposite charges attract, the same charges repel
Circuit diagrams should be drawn with a pencil and ruler. Component symbols are used.
Current is the flow of electrons. Potential difference is the energy these electrons have.
In a series circuit, components are connected in a single loop, so the current can take only
one route around the circuit. Current is the same in all parts of the circuit.
In a parallel circuit, components are connected on separate branches, so the current can
take different routes around the circuit. Current is different in different pats of the circuit.
As resistance increases in a circuit, the current decreases.
Opposite poles of magnets attract. The same poles repel.
Electromagnets are made by wrapping wire around an iron bar and passing current through
the coil.
Uses of electromagnets include automatic door locks, scrap yard cranes and levitating trains.
Protons (+ve charge relative mass of 1) Neutrons (No charge, relative mass of 1) Electrons (–ve
charge, insignificant mass)
Number of protons = atomic number and Number of electrons = atomic number
Number of electrons = mass number - atomic number
Reactivity series: Magnesium → Aluminium → Zinc → Iron → lead → Copper → Silver → Gold
In a displacement reaction a more reactive element pushes out a less reactive element
Solid (s), liquid (l), gas (g), dissolved in water (aq)
Metal + acid → salt + hydrogen
Metal + water → metal hydroxide + hydrogen
Metal + oxygen → metal oxide
Combustion: fuel + oxygen → carbon dioxide + water
