A horizontal row in the periodic table is called what?
A period
100
Atoms with the same number of protons but different number of neutrons.
What are isotopes?
100
Name the three subatomic particles.
Protons, neutrons, and electrons
100
The number of protons in an atom of a certain element.
What is atomic number?
100
Greek man from 450BC who said matter is composed of tiny invisible particles called atoms.
Who was Democritus?
200
A vertical column in the periodic table is called a what?
A group or family
200
Since atoms are electrically neutral, the numbers of which 2 subatomic particles are equal to each other?
Protons and electrons
10+ and 10- add up to 0
200
These particles are located outside of the nucleus, have no mass, and have a -1 charge.
Electrons?
200
The sum of protons and neutrons in the nucleus of an atom of any element.
What is the mass number?
200
One part of Dalton's 4-part theory of atoms included the idea that atoms can chemically combine in what type of ratios?
Whole number ratios
300
The properties of elements in a row of the periodic table do this as you move across the row.
They vary or change
300
How many protons are present in an atom of Iron-58? The symbol for iron is Fe.
26
Iron is element number 26, so it has 26 protons.
300
These particles are located inside of the nucleus, have a mass of 1 amu, and have a +1 charge.
Protons
300
The atomic number of Oxygen.
What is 8?
300
Famous for flying a kite in a thunderstorm, he discovered properties of electrical charges, such as, like charges repel and opposite charges attract each other.
Who was Ben Franklin?
400
The properties of the elements in a column of the periodic table are this.
Similar to each other, like you are similar to your family members.
400
What is the mass number of an isotope of silicon (Si) which has 16 neutrons?
30
Mass Number = protons + neutrons = 14 + 16 = 30
400
Atoms of different elements have different numbers of these.
Protons
400
This number is a calculated "weighted average" of mass numbers and percent abundances of an element's isotopes.
What is Average Atomic Mass?
400
His experiments with cathode ray tubes led to his discovery of the electron.
Who was Thomson?
500
The elements in the periodic table are arranged based on their what?
Properties
500
How many neutrons are present in an atom of Calcium-42? The symbol for calcium is Ca.
22
Mass Number - Protons = 42 - 20 = 22 neutrons
500
These particles are located inside of the nucleus, have a mass of 1 amu, and have no charge.
Neutrons
500
Mass number - atomic number = ______________
Number of neutrons
500
Rutherford's Gold Foil Experiment provided evidence for what part of the atom?