Atomic Bases
What is the smallest unit of an element that keeps its properties?
Atom
What is the positively charged particle called?
Proton
What number that how many protons an atom has?
Atomic Number
Who is the Greek thinker who first suggested atoms?
Democritus
What are atoms of the same element with different numbers of neutrons called?
Isotopes
What is the center of the atom that contains most of its mass called?
Nucleus
What is the particle with no charge called?
Neutron
What number do you round to find neutrons?
Atomic Mass
What is Rutherford’s discovery about atom structure?
Atom is mostly empty space with a small dense nucleus.
Why is atomic mass a decimal?
What is the region where electrons are found around the nucleus called?
Energy Levels (Shells)
What is the lightest subatomic particle?
Electron
How do you calculate neutrons?
Which scientist who created the first modern atomic theory?
John Dalton
The most common isotope is closest to this value
Atomic mass
Why are atoms usually neutral?
They have equal numbers of protons and electrons.
Where are protons and neutrons found?
Nucleus
How many electrons are in a neutral oxygen atom?
8
What was Bohr’s idea about how electrons move?
How many neutrons are in an atom with 17 protons and mass 35?
18
What happens when an atom gains or loses electrons?
It becomes an ion.
What is responsible for most of an atom’s mass?
Protons and Neutrons
What does the atomic number determine?
The identity of the element.
Cathode ray tubes
Why do isotopes have different masses?
Different number of neutrons