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