Flashcards
C1 flashcards
Flashcards do conjunto (31)
- 1What are the properties of solids?strong forces of attraction
fixed positions in a regular lattice arrangement
keep definite shape and volume
can only vibrate - 2What happens to solids when the temperature is increased?They vibrate more and expand slightly. If enough energy is provided the solid will melt and become a liquid.
- 3What are the properties of liquids?There is some force of attraction
They are free to move, but often stick together
Particles constantly moving with random motion
Don't keep a definite shape - 4What happens when a liquid is heated?They will move faster and expand slightly
It will evaporate (or boil) to become a gas. - 5What happens when you cool a liquid?It will freeze and become solid.
- 6What are the properties of gasses?There is no force of attraction
Particles are free to move
They travel in straight lines and only interact when they collide
Don't keep a definite shape or volume, they will fill any container
In a constant random movement
Exert a pressure on container walls when they collide - 7What happens when you heat a gas?They move faster
They either expand when heated or their pressure increases - 8What happens when you cool a gas?It will condense and become a liquid.
- 9What are the flaws with the particle model?Particles aren't solid or spheres
Doesn't give any idea about the size of particles or the space between them
Doesn't show forces between particles - 10What is a physical change? (give example)No new substances are made
The original chemical changes states
They are reversible
The original substance can be retrieved
State changes are physical changes
Melting, boiling, condensing and freezing are physical changes. - 11What is a chemical reaction?The bonds between atoms are rearranged
A new substance is formed
They are irreversible - 12What was John Dalton's model of the atom?He described atoms as solid spheres
He said different spheres made up different elements
This theory was made in the early 19th century - 13What was J J Thompson's model of the atom and when did he make his model?1897
He discovered electrons and made a 'plum pudding model'
There were electrons within a positively charged pudding - 14How did Ernest Rutherford show the plum pudding model was incorrect?He fired +charged alpha particles at a sheet of gold foil, they should have passed straight through but some were deflected and some were deflected backwards.
There must be a positively charged nucleus at the centre
This model had a small nucleus surrounded by a cloud of electrons - 15How was Rutherford's model disproved?Scientist's realised an atom would collapse since the electrons would be attracted to the nucleus.
- 16What was Neil Bohr's model?He proposed electron orbits and shells
Each shell has a fixed energy
Many experiments supported this - 17How do scientific models change?New evidence and experiments prompt new ideas and improving theories.
Predictions can be made with new ideas
Peer review
Can improve their own and others research - 18What are protons and what are the properties of protons?Positively charged subatomic particles
Have a relative mass of 1
Have a relative charge of +1 - 19What are neutrons and what are the properties of neutrons?Neutral subatomic particles
Have no relative charge
Have a relative mass of 1 - 20What are electrons and what are their properties?Electrons are negatively charged subatomic particles
Thy have a relative charge of -1
They have a relative mass of 0.0005 - 21Where is the nucleus located, what is found in the nucleus and what are the properties of the nucleus?In the middle of an atom
Contains protons and neutrons
Has a positive charge due to protons
Almost all of an atoms mass is concentrated in the nucleus (about 10 to the negative 23 g)
The nucleus is tiny compared to the overall size of an atom (radius is about 10 to the negative 15 m) - 22Where are electrons found in the atom, and what are their properties?Move around nucleus in electron shells
Negatively charged
Orbits cover a lot of space
The volume of their orbitals determine the size of an atom
Electrons have virtually no mass (often taken as zero) - 23What are molecules?Two or more atoms bonded together
- 24What does the mass number tell us?It tells us the number of protons and neutrons in an atom.
It is always the biggest number
On a periodic table the mass number is the relative atomic mass - 25What does the atomic number tell us?It tells you the number of protons
Atoms of the same elements all have the same number of protons - 26How do you work out the number of neutrons in an atom?Subtract the atomic number from the mass number.
- 27What are ions and how are they formed?Ions are charged atoms.
The gain or lose electrons and become either negatively or positively charged. - 28How are positive ions formed, and why are are they positive?They are formed by loosing electrons.
Since they have more protons than electrons the are positive. - 29How are negatively charged ions formed, and why are they negative?They are formed by gaining electrons.
They are negatively charged since there are more electrons than protons. - 30What are isotopes?Isotopes are different forms of the same elements.
They have a different number of neutrons and the same number of protons. - 31What are the two main isotopes of carbon?Carbon-12
has 6 protons
has 6 electrons
has 6 neutrons
Carbon-13
has 6 protons
has 6 electrons
has 7 neutrons
Informações
- Descrição
- OCR combined science GCSE chemistry, unit 1
- Criado por
- sad face · jun 2021
- Atualizado
- 10 jun 2021
- Visualizações
- 3
- Avaliação