Atomic Structure (Chemistry) Flashcards
What did Neils Bohr discover?
That electrons orbited the nucleus at specific distances, called shells
What subatomic particles have no charge?
Neutrons
What number tells us how many protons there are in an atom?
The atomic number
What subatomic particles have a charge of +1?
Protons
The discovery of what lead to scientists not accepting the Dalton model of the atom anymore?
Electrons, as they were smaller than the atom.
What is the smallest part of an element that can exist?
An atom
Why do scientists know that the Dalton model of the atom isn’t correct?
Other scientists have done many experiments to show the Dalton Model doesn’t fit
What does the mass number tell us about the atom?
The number of protons PLUS the number of neutrons.
What word means the same as electron shell?
energy level
How many different elements are there?
About 100
What is the relative mass of an electron?
0
How are compounds formed?
From chemical reactions where bonds are broken and then reformed.
What is a substance made of only one type of atom?
An element
What are the 3 forms that substances can exist in?
Elements Compounds Mixtures
What did James Chadwick discover?
The neutrons in the nucleus
What can never be the same for 2 different elements?
The atomic number, or the number of protons.
What is the plum pudding model of the atom?
A ball of positive charge with negative electrons studded into it.
How many letters are there in a chemical symbol?
One or two depending on the element.
What is the charge of an electron?
negative 1 (-1)
What subatomic particles have a charge of -1?
Electrons
What experiment disproved the plum pudding model?
The gold foil experiment
What model became accepted after the gold foil experiment?
The nuclear model