Atoms Flashcards
The word atom comes from which greek word and what does it mean?
Atomos which means indivisible (cannot be divided)
Which model stated that an atom is a very small, hard sphere that is indivisible?
The Dalton Model, 1803
Which model stated that an atom is a continuous mass of positive charge containing negative electrons?
Thomson’s Model 1897
Which model stated that an atom has a nucleus surrounded by electrons?
Rutherford’s Model 1911
Which model stated that an atom has a nucleus & electrons move in fixed orbitals around the nucleus?
Bohr’s Model, 1915
Which model of an atom do we use today?
Bohr’s Model
Atoms are made of three subatomic particles what are they?
electrons, protons, and neutrons
What kind of charge don electrons have?
negative
What kind of charge do protons have?
positive
what kind of charge do neutrons have?
no charge, they’re neutral
Which two subatomic particles make up the nucleus?
The neutron and protons
Why is an atom electrically neutral?
Because the number of electrons which are negatively charged are equal to the number of protons which are positively charged.
What is the relative mass of proton?
1
What is the relative mass of neutrons?
1
What is the relative mass of electrons?
1/1836
