This theory says all matter is made of tiny particles that are always moving.
What is the Particle Theory of Matter?
This type of mixture looks uniform and cannot easily be separated.
What is a homogeneous mixture?
Melting ice into water is this kind of change.
What is a physical change?
This is the smallest part of an element that still remains that element.
What is an atom?
This Greek philosopher first suggested everything was made of tiny particles.
Who is Democritus?
These particles are free-moving and have no fixed shape or volume.
What is a gas?
Salt in salt water is called this.
What is a solute?
Rusting and burning are examples of this type of change.
What is a chemical change?
The centre of an atom containing protons and neutrons.
What is the nucleus?
This scientist discovered the electron and proposed the plum pudding model.
Who is J.J. Thompson?
This state has particles stuck together enough to keep a fixed volume but not a fixed shape.
What is a liquid?
Milk and fog are examples of this type of mechanical mixture.
What are colloids?
A property like density or boiling point is an example of this.
What is a physical property?
The atomic number equals the number of these in an atom.
What are protons?
This scientist made the gold foil experiment and the planetary model.
Who is Ernest Rutherford?
According to particle theory, particles do this when they get very close together.
What is repel each other?
Steel is an example of this kind of homogeneous mixture containing a metal.
What is an alloy?
This type of property includes combustibility and reactivity.
What is a chemical property?
Horizontal rows on the periodic table are called these.
What are periods?
This scientist proposed electrons exist in stable energy levels.
Who is Neil Bohr?
Ice, water, and steam are examples used to compare these three states.
What are solid, liquid, and gas?
This type of matter contains only one kind of particle throughout.
What is a pure substance?
Name two signs that a chemical change may have happened.
What are a new colour appearing and a temperature change on its own?
This line on the periodic table separates metals and nonmetals.
What is the staircase?
This scientist developed the model where electrons exist in orbitals with specific shapes and levels.
Who is Erwin Schrodinger?