Unit 1: Atoms and Atomic Structure

What is a negatively charge subatomic particle?

• Electron

• Neutron

• Proton

A positively charged subatomic particle is called?

• Neutron

• Electron

• Proton

A neutral subatomic particle is called

• Neutron

• Electron

• Proton

(2 right answers) How did the concept of the atom change from the time of Democritus to the time of John Dalton?

• Democritus lacked experimental support and was not based on the scientific method.

• Democritus explained chemical behavior using experimental support

• Democritus reasoned atoms could be divisible and indestructible

• Democritus reasoned that atoms were indivisible and indestructible.

How do you find atomic number?

• The number of protons in an atom

• Electrons in the outermost energy level of an atom

• A subatomic particle that has a positive charge and is found in the nucleus of an atom

• the mass before a chemical reaction is equal to the mass after a chemical reaction

How do you find the mass number?

• Bands of light formed as excited electrons return to ground state; used to identify elements

• The sum of the protons and neutrons

• A subatomic particle that has a positive charge and is found in the nucleus of an atom

• Atoms of the same element with different mass numbers due to varying numbers of neutrons

What two subatomic particles are located in the Nucleus?

• Protons and

• Neutrons and Electrons

• Protons and Neutrons

• Quarks and Electrons

Who was the first person to propose the idea of an Atom?

• Niels Bohr

• Democritus

• John Dalton

• J.J Thomson

How do you find Atomic Mass?

• A charged atom that has lost or gained an electron

• the weighted average of the masses of an element's naturally-occurring isotopes

• small, dense, positively-charged center of an atom

• 3D region where electrons are found

The small, dense, positively-charged center of an atom is called

• Nucleus

• Elect

• Proton

• Electron Cloud