DALTON'S ATOMIC THEORY
According to Dalton, all matter is made of these tiny particles.
atoms
This scientist proposed the "plum pudding" model of the atom.
J. J. Thomson
This subatomic particle has a negative charge.
electron
The number of protons in an atom is called its __________.
atomic number
An atom has 2 protons, 2 neutrons, and 2 electrons. What element is it?
Helium
Dalton believed that atoms of the same element are this.
Identical
Thomson's model described the atom as a sphere of positive charge with these particles scattered throughout it.
electrons?
This subatomic particle has a positive charge and is found in the nucleus
proton
The number of protons plus the number of neutrons is called the __________.
mass number?
An atom has 11 protons, 12 neutrons, and 11 electrons. What is its mass number?
23
According to Dalton's theory, atoms of different elements are ________.
Different
This scientist performed the famous gold foil experiment.
Ernest Rutherford
This subatomic particle has no charge and is found in the nucleus
neutron
An atom has 6 protons, 6 neutrons, and 6 electrons. What is its atomic number?
6
An atom has 12 protons, 12 neutrons, and 12 electrons. What is its atomic number?
12
Dalton said that atoms combine in simple whole-number ratios to form these.
Compounds
Rutherford's gold foil experiment led scientists to conclude that most of the atom is this.
empty space
The proton and neutron are found in this part of the atom
nucleus
An atom has 8 protons, 10 neutrons, and 8 electrons. What is its mass number?
18
An atom has 15 protons, 16 neutrons, and 15 electrons. Identify the element and its mass number.
Phosphorus; mass number = 31
According to Dalton's original theory, atoms could not be created, destroyed, or _______ during a chemical reaction.
Divided
Rutherford's model replaced Thomson's plum pudding model with a small, dense, positively charged center called this.
nucleus
Which subatomic particle determines what element an atom is
proton
An atom has 17 protons, 18 neutrons, and 17 electrons. Identify the element AND give its mass number.
Chlorine; mass number = 35
An atom has 20 protons, 20 neutrons, and 20 electrons. Identify the element, atomic number, and mass number.
Element: Calcium
Atomic number: 20
Mass number: 40