Copy of Year 9 Mid Point Assessment Core Qs Chemistry only 24_25 - Chemistry Flashcards
What is an element?
Substance made from only one type of atom.
What is a compound?
Substance made from different types of atoms that are chemically combined.
What is a pure substance?
A substance where all the particles are the same.
What is a mixture?
Contains different elements or compounds which are not chemically combined.
What is a physical change?
Where the state changes but the chemical remains the same.
What is a chemical change?
Where a new chemical substance is formed.
What is a solution?
A mixture that contains a solute and solvent.
What is filtration?
Separating a solid from a liquid or gas
How do you separate salt from a mixture of salt water?
Evaporation of the water/distillation
What is chromatography?
A separation technique that separates based upon the solubility of a substance.
What is an atom?
A particle made of protons, neutrons and electrons
What are the three subatomic particles?
Protons, neutrons and electrons
How are the subatomic particles arranged in an atom?
Protons and neutrons in a nucleus, electrons travel around the nucleus in shells
What is between the nucleus and the shells?
Empty space
How can atoms be different to each other?
In the number of protons, neutrons and electrons they have
What charge does an electron have?
Negative charge (-1)
What charge does a proton have?
Positive charge ({+1)
What charge does a neutron have?
No charge(0)
Why do atoms have no overall charge?
The number of protons always equals the number of electrons in an atom.
What is the atomic number?
This is the number of protons.
What is the mass number?
This is the total number of protons and neutrons.
Which number identifies the element?
The atomic number.
What is the maximum number of electrons that the first shell can have?
2
What is the maximum number of electrons that the second shell can have?
8