Atomic Theory/Structure

The first person to propose the concept of the atom or "atomos" and said atoms were indivisible was 

• Rutherford
• Dalton
• Democritus
• Bohr

Which idea of Dalton's is no longer considered part of the modern view of atoms?

• Atoms are extremely small
• Atoms of the same element have identical masses
• Atoms combine in simple whole number ratios to form compounds
• Atoms of different elements can combine in different ratios to form compounds

Ernest Rutherford devised an experiment in 1911 to probe the structure of an atom. What did he discover using gold foil?

• Electrons
• Neutrons 
• nucleus
• orbits

The person who developed the planetary model and stated that electrons move in circular orbits was

• Thomson
• Bohr
• Rutherford
• Dalton

The region of the atom that contains the most mass is 

• electron cloud
• nucleus
• neutron
• proton

Elements are identified by their number of protons, which is equal to the 

• atomic number
• mass number
• volume
• density number

Which best describes the current (electron cloud) theory?

• Atoms consist of electrons circling in definite orbits around the nucleus
• atoms are composed of electrons in a cloud around a positive nucleus
• atoms can be easily split, at which time they become radioactive
• an atom's mass is determined by its nucleus

Isotopes are atoms of the same element that differ in the number of 

• protons
• neutrons
• electrons
• ions

Tags

NGSS.HS-PS1-8

The nucleus of the atom consists of 

• only protons
• protons and neutrons
• electrons and neutrons
• protons and electrons

For an atom to be electrically neutral, the numbers of which particles must be equal?

• protons and neutrons
• neutrons and electrons
• protons and electrons
• all must be equal