Particles - Particle theory/Atomic structure Flashcards
What was John Dalton famous for?
He was famous for his theory that all matter was made of tiny particles called atoms.
During chemical reactions, what do atoms do to create new substances?
They rearrange themselves.
What does an atom consist of?
An atom consists of positively charged nucleus. Also, they are surrounded by negatively charged electrons.
What are subatomic particles?
Subatomic particles are objects that are found in atoms. For example, protons, neutrons and electrons.
What is relative mass?
A relative mass is the number of times heavier a particle is compared to another.
What is the atomic number?
Atomic number of an atom is the number of protons in the nucleus.
Why are atoms neutral?
The electrons and protons are equal.
Calculation for neutrons.
Neutrons = Mass number - atomic number.
What are isotopes?
An isotope is the atoms of an element with the same electron and proton number, but different neutron number.
What do the number of electrons determine?
The number of electrons determine the chemical properties and the atoms of all three isotopes have one electron.
What are ions?
Ions are charged particles that get formed when atoms or a group of atoms lose or gain electrons.
What happens when electrons are lost?
Positively charged ions are formed.
What happens when protons are lost?
Negatively charged ions are formed.
What does the 3+ in “Al^3+” represent?
It represents the number of positively charged ions.
What particles are found most in atoms?
Protons and neutrons.
