Who said that "electrons can only occupy certain orbits in the atomic shell"?
Niels Bohr
What did Democritus think the world was made up of?
small particles called atoms
Protons have the same mass as ...?
neutrons
What is the electric charge of electrons?
negative charge
What letters represent the different energy sublevels in an atom?
s, p, d, f, g
Almost all the mass of the atom is in the _________? (in Rutherford's model)
nucleus
True or false: Atoms X (Z=19 A=40) and Y (Z=20 A=40) are isotopes.
False
Inside the nucleus of an atom, you will find ...?
neutrons and protons
What is the maximum number of electrons in a p sublevel?
6
Dalton believed that matter is made up of indivisible particles that cannot be _________
destroyed
Who was the first person to study atoms using the scientific method?
Dalton
Describe the planetary model.
describe
Dalton said that atoms of different elements can come together to form _________
compounds
What is the maximum number of electrons in the 4th level?
32
Rutherford's atomic model is usually known as ...?
the planetary model
When an atom has less electrons that protons, it is called a __________?
cation
In Rutherford's model, where are the protons, neutrons and electrons?
Protons and neutrons in the centre, electrons outside
The electrons fill the levels and sublevels, starting with the level .... (closest/furthest) to the nucleus.
Closest
The symbol for the atomic number is ...
Z
That is the distribution of electrons in the 3rd level?
2 6 10
The atomic number is the total number of ...?
protons in an atom
True or false: Stable isotopes break up over time emitting particles or electromagnetic radiation.
True
Compounds are always made up of atoms of the same element?
No, for example H2O
In which sublevel is the last electron of a calcium atom (Z=20)?
3p
Dalton believed that atoms of the same element were all the same. In what way are they the same?
They have the same mass, size and properties
The mass number is the total number of ...?
protons AND neutrons added together
True or false: The electron configuration for silicon (Z=14) is 1s2 2s2 2p6 3s1 3p1
False
The symbol for the mass number is ...
A
Describe Daltons atomic model
He thought that atoms are tiny hard spheres
Where was Democritus from?
Ancient Greece
When an atom has more electrons than protons, it is called an ________
anion
Thomson said that atoms are neutral because ...?
the number of positive protons is equal to the number of negative electrons
What can you find inside the atom, between the nucleus and the electrons? (in Rutherford's model)
nothing, that space is empty
What did Rutherford call the centre of the atom?
a nucleus
Did Dalton believe that atoms were soft like pudding or hard little balls?
He believed that they were tiny hard spheres
True or false: Isotopes can be stable and unstable.
True
Can some atoms have more electrons than protons?
Yes
In Rutherford's atomic model, the electrons are _______ing around the nucleus.
orbit(ing)
Did Dalton use the scientific method to study atoms?
Yes
True or false: Are the atoms X (6 protons and 6 neutrons) and Y (7 protons and 5 neutrons) the same element?
False
Who said that "the positive charge of atoms in concentrated in a tiny central area"?
Rutherford
True or false: Atoms X (Z=20 A=40) and Y (Z=20 A=41) are isotopes.
True
Is C-14 a radioactive isotope?
True
Do neutrons have an electric charge?
no, they don't