A) their masses are always equal. B) each element contributes an equal number of atoms. C) the ratio of their masses is always the same. D) their volumes are always equal.
A) Negative and positive charges are spread evenly throughout an atom. B) There is a dense, positively charged mass in the center of an atom. C) Gold is not as dense as previously thought. D) Alpha particles have a positive charge.
A) spread evenly throughout an atom. B) located in the space outside the nucleus. C) concentrated in the center of an atom. D) concentrated at multiple sites in an atom.
A) proton B) electron C) neutron
A) Unlike protons or neutrons, electrons have no mass. B) An electron has far less mass then either a proton or a neutron. C) Neutrons have no charge and no mass. D) Protons, neutrons, and electrons all have about the same mass.
A) the number of protons B) the number of neutrons C) the mass of the neutron D) the charge on the electrons
A) mass number B) isotope C) atomic number D) charge
A) isotope number from atomic number B) atomic number from mass number C) atomic number from electron number D) mass number from atomic number
A) like popcorn in a popper. B) like planets orbiting the sun. C) like balls rolling down a hill. D) like beach balls on water waves.
A) the number of electrons in an atom B) the precise location of electrons in an atom C) the most likely locations of electrons in an atom D) the mass of the electrons in the atom
A) the are extremely nonreactive B) they form negative ions C) they are located in the left-most column of the periodic table D) they are usually gases
A) volume of a substance B) electric charge of a substance C) mass of a substance D) amount of a substance
A) isotope number B) atomic number C) mass number D) atomic mass unit
A) its atomic mass B) the ratio of protons to neutrons in atoms of the element C) the number of valence electrons in atoms of the element D) how tightly atoms are packed in the element
A) They have the same mass number B) They are isotopes of oxygen C) they do not have the same number of protons D) their masses are identical
A) element to element B) row to row C) column to column D) group to group
A) phosphorus, nitrogen, oxygen B) sodium, chromium, copper C) helium, carbon, gold D) iodine, iron, nickel
A) the immediate acceptance by other scientists. B) the discovery of elements with predicted properties. C) the discovery of subatomic particles. D) the discovery of the nucleus.
A) two B) three C) four D) none
A) decreases B) increases then decreases C) increases D) stays the same
A) chlorine-35 atom B) neutron C) carbon-12 atom D) proton
A) -1 B) +1 C) -2 D) 0
A) 1 B) 0 C) 1/1840 D) 1/18
A) number of neutrons B) period C) mass D) chemical properties
A) changing from one period to another B) changing from lithium into fluorine C) losing or gaining electrons D) losing or gaining protons
A) one-twelfth the mass of a carbon-12 atom B) one-fourth the mass of a lithium atom C) one-fifteenth the mass of a nitrogen-15 atom D) one-half the mass of a hydrogen atom
A) they are rare in nature B) they can form compounds with bright colors C) They exist as single elements rather than molecules D) they are highly reactive
A) have large atomic masses but small atomic numbers B) are extremely hard C) can conduct electric current only under certain conditions D) do not form compounds
A) on the right B) on the left C) in the middle D) on the bottom
A) one kilogram of a pure substance. B) one mole of a pure substance C) one gram of a pure substance D) one liter of a pure substance
A) 35 B) 172 C) 80 D) 79
|