C1 Flashcards
Describe the movement of particles in solids
Vibrate around fixed positions
Describe the arrangement of particles in liquids
Random and close
Describe the arrangement of particles in solids
Regular and very close
What are two differences between chemical and physical changes?
Chemical changes are irreversible, and a new substance is made. Physical changes are reversible and no new substance is made.
What are three limitations of the particle model?
It does not take into account the forces between particles, the size of particles and the space between particles.
What is the relative charge of a proton?
+1
What is the relative size of a proton?
1
What is the relative size of an electron?
0.0005
What is the relative charge of an electron?
-1
What is the relative mass of a neutron?
1
What is the relative charge of a neutron?
0
What does atomic number tell you?
The number of protons in the nucleus
What does mass number/ atomic mass tell you?
Total number of protons and neutrons in the nucleus
What is the symbol for atomic number?
Z
What are isotopes?
Different atomic forms of the same element with the same number of protons but a different number of neutrons.
How do you calculate the number of neutrons?
Mass number take away atomic number
What are ions?
Charged particles formed when atoms (or molecules) gain or lose electrons
Why are some ions positive?
They have lost electrons
Why are some ions negative?
They have gained electrons
What did Neils Bohr add to the model of the atom
Electrons orbit in shells or energy levels
What evidence is there that the atom is mostly empty space?
Most alpha particles passed straight through in Rutherford’s gold leaf experiment
Which subatomic particle did JJ Thomson discover?
The electron
How do you calculate the ratio of distance to diameter?
Distance between atoms divided by diameter of atom
