chemistry

Who suggested that there were four basic substances from which all other substances are created by mixing them together?

• Plato

• Democritus

• Empedocles

• Aristotle

Which Greek philosopher proposed that all matter is made up of very small particles called atoms?

• Democritus

• Plato

• Aristotle

• Empedocles

Who discovered the electron by experimenting with a Crookes, or cathode ray, tube?

• John Joseph Thomson

• Ernest Rutherford

• Niels Bohr

• Henry Moseley

Who proposed an atomic model that shows electrons move in concentric orbits around the nucleus?

• Niels Bohr

• Ernest Rutherford

• John Joseph Thomson

• Henry Moseley

What is the type of bond formed by the complete transfer of valence electron(s) between atoms?

• Hydrogen bonding

• Metallic bonding

• Covalent bond

• Ionic bond

What is the type of covalent bonding that occurs between atoms of metals, in which the valence electrons are free to move through the lattice?

• Ionic bond

• Hydrogen bonding

• Metallic bonding

• Covalent bond

What is the type of covalent bonding that specifically occurs between atoms of slightly different electronegativities sharing electrons?

• Ionic bond

• Metallic bonding

• Polar covalent bond

• Nonpolar covalent bond

What is the special kind of dipole-dipole interaction that occurs specifically between a hydrogen atom bonded to either an oxygen, nitrogen, or fluorine atom?

• Metallic bonding

• Dipole-dipole interactions

• Hydrogen bonding

• London dispersion forces

What is the type of force that occurs when the partially positively charged part of a molecule interacts with the partially negatively charged part of the neighboring molecule?

• Metallic bonding

• Dipole-dipole interactions

• Hydrogen bonding

• London dispersion forces

Who discovered the nucleus of the atom in 1911?

• John Joseph Thomson

• Ernest Rutherford

• Henry Moseley

• Niels Bohr