Show:
Atomic Theory Scientists
Subatomic Particles
Isotopes and More
Find that Element
100
This scientist discovered the electron.
Who is JJ Thomson?
100
This particle has a positive charge.
What is a proton?
100

Atoms of the same element with a different number of neutrons.

What is an isotope?

100

This element has 20 protons.

What is Calcium (Ca)?

200

This scientist proposed that there is a positively charged nucleus and that electrons orbit the nucleus just like planets orbit the sun.

Who is Ernest Rutherford?

200

This particle has no charge and its only contribution to the atom is to give the atom more mass.

What is a neutron?

200
The atomic number is the same as the number of this particle.
What is a proton?
200

This elements atom has 6 electrons

What is Carbon (C)?

300
This scientist described the atom as the smallest, most indivisible piece of matter and proposed 4 postulates/laws regarding atomic theory.
Who is John Dalton?
300

This particle has a negative charge and has a negligible mass. 

What is an electron?

300

The mass of Oxygen with 8 protons and 10 neutrons

What is Oxygen-18?

300

This element has 30 electrons

What is Zinc (Zn)?

400

This scientist found the charge and the mass of an electron using the Oil Drop Experiment. 

Who is Robert Millikan?

400

This particle identifies what type of element an atom is.

What are protons?

400

This is the formula to find the atomic mass of an atom.

What is # of protons + # neutrons?

400

This element has 84 protons and neutrons combined. 

What is Krypton (Kr)?

500
An ancient Greek philosopher who theorized that there must be some particle that is the smallest form of matter and called it "atomos".
Who is Democritus?
500

This particle contributes mostly to the volume of the atom.

What is an electron?

500
Magnesium-25 has this number of neutrons
What is 13 neutrons?
500

The element with 23 protons and neutrons combined?

What is Sodium (Na)?