C1 - The atom Flashcards
(24 cards)
What is an atom?
The smallest part of an element to keep its properties
What is Dalton’s model of the atom?
Atoms are small spheres that can’t be divided
Describe the plum pudding model
Sphere of positive charge with negative electrons embedded throughout it
What did the alpha scattering experiment prove?
The atom’s mass and positive charge is concentrated in a small space
Describe the nuclear model of the atom
A dense nucleus with electrons orbiting it
What did Bohr discover?
Electrons in shells
What did Chadwick discover?
Neutral particles (neutrons)
What is in the nucleus?
Protons and neutrons
What is the relative mass of a proton?
1
What is the relative mass of a neutron?
1
What is the relative mass of an electron?
Negligible
What is the charge of a proton?
+1
What is the charge of a neutron?
0
What is the charge of an electron?
-1
What is the atomic number?
The number of protons in an atom
How do you find the number of neutrons in an atom?
Mass number - atomic number
Why do atoms have no overall charge?
They have equal numbers of protons and electrons
How many electrons go in the first three shells?
2,8,8
What is an element?
A substance made from one type of atom
What is a compound?
A substance made from more than one type of atom chemically joined together
What is a mixture?
Two or more substances not chemically joined
What are isotopes?
Atoms of the same element with different numbers of neutrons
How can mixtures be separated?
Filtration, distillation, fractional distillation, crystallisation, chromatography
What is relative mass?
The mass of all the atoms in an element
