Who was the philosopher that thought matter was made up of tiny particles but did not conduct experiments to test this idea?

• Aristotle

• Democritus

• Plato

• Socrates

What term did Muslim scholars use to describe the process of purifying metals and combining substances?

• Chemistry

• Alchemy

• Al-kimia

• Metallurgy

What did J.J. Thomson observe in cathode ray tubes that led him to suspect the presence of particles smaller than atoms?

• The gas in the tube was easy to energize

• The beam bent toward positively charged plates

• The beam moved in a straight line

• The beam was unaffected by magnetic fields

What did the Maya in Central America notice about some plants when heated?

• They changed color

• They emitted light

• They had unique properties

• They became liquid

What term is used to describe particles that are even smaller than an atom?

• Macroparticles

• Isotopes

• Subatomic particles

• Molecules

Which subatomic particle is positively charged?

• Electron

• Proton

• Neutron

• Photon

How does the mass of an electron compare to that of a proton?

• Electrons are twice as massive as protons.

• Electrons have the same mass as protons.

• Electrons are 1/2,000th the mass of a proton.

• Electrons are 1/200th the mass of a proton.

What is the role of neutrons in the nucleus of an atom?

• They provide a positive charge.

• They repel electrons.

• They add mass and stability.

• They orbit the nucleus.

What did scientists learn about the structure of the atom from Rutherford's experiment?

• Electrons are located in the nucleus.

• The nucleus is negatively charged.

• The nucleus is dense and positively charged.

• Atoms do not contain empty space.

What has changed over time regarding our understanding of atomic structure?

• The size of atoms

• The color of atoms

• The model of atomic structure

• The weight of atoms