Famous Scientists
He's an ancient Greek who came up with the term atom.
Who is Democritus?
What is a proton?
This is the smaller number shown for an element and is always a whole number.
What is the atomic number?
This is the basic building block of matter.
What is an atom?
A material containing just one element or compound.
What is a pure substance?
He discovered the electron in his cathode ray gun experiment.
Who is Thomson?
This particle contributes a negative charge to an atom.
What is an electron?
This number is the larger of the two numbers and includes a decimal.
What is the atomic mass (or atomic weight)?
A substance made up of all the same type of atom.
What is an element?
This material CAN be separated by physical means (filtration, evaporation etc)
What is a mixture?
He discovered positively charged particles called protons forming a nucleus.
Who is Rutheford?
This particle adds mass to the nucleus, in addition to a proton.
What is a neutron?
The atomic number represents this in an atom of the element.
What is the number of protons?
Must have at least 2 different types of atoms bonded together.
What is a compound?
This type of mixture is uniform in appearance (eg air, salt water)
What is homogeneous?
He pioneered the idea of electrons in specific energy levels or shells.
Who is Bohr?
An atom becomes this when it no longer has a neutral charge.
Elements in the same columns tend to have this in common, helping to predict behavior.
What are valence electrons?
What is a molecule?
An ice cream sundae is this type of mixture.
What is heterogeneous?
He contributed to the development of the electron cloud model, developing his famous "Uncertainty Principle".
Who is Heisenberg?
An atom becomes this when it has more protons than electrons.
What is a cation?
What is the term used for the collection of elements in the far right column?
What are Noble Gases?
If a substance is an element, it cannot also be this.
What is a compound.
(I'll accept mixture too)
Substances that can only be decomposed down by breaking chemical bonds.
What are compounds?