Questions | Answer | Explanations |
1 Which subatomic particle is negatively charged?
(1) electron (3) positron
(2) neutron (4) proton | 1 | electrons are negative |
2 Which element has the greatest density at STP?
(1) barium (3) magnesium
(2) beryllium (4) radium | 4 | use TABLE S |
3 What is the mass number of a carbon atom that contains six protons, eight neutrons, and six electrons?
(1) 6 (3) 14
(2) 8 (4) 20 | 3 | Mass Number= protons + neutrons |
4 Which element is a metalloid?
(1) Al (3) As
(2) Ar (4) Au | 3 | on the staircase, not Al or the radioactive Po or At |
5 Which substance can be decomposed by chemical means?
(1) aluminum (3) silicon
(2) octane (4) xenon | 2 | DEFINITION-compounds |
6 An element that is malleable and a good conductor of heat and electricity could have an atomic number of
(1) 16 (3) 29
(2) 18 (4) 35 | 3 | Metal properties |
7 A 1.0-mole sample of krypton gas has a mass of
(1) 19 g (3) 39 g
(2) 36 g (4) 84 g | 4 | Atomic Mass= mass of 1 mole of an element |
8 An atom in the ground state has a stable valence electron configuration. This atom could be an atom of
(1)Al (3) Na
(2) Cl (4) Ne | 4 | Stable is 8 valance electrons, Group 18 |
9 An atom of an element has a total of 12 electrons. An ion of the same element has a total of 10 electrons. Which statement describes the charge and radius of the ion?
(1) The ion is positively charged and its radius is smaller than the radius of the atom.
(2) The ion is positively charged and its radius is larger than the radius of the atom.
(3) The ion is negatively charged and its radius is smaller than the radius of the atom.
(4) The ion is negatively charged and its radius is larger than the radius of the atom. | 1 | First the atom is Mg the ion is 2+ and it loses 2 electrons and get smaller |
10 Which formula represents a nonpolar molecule?
(1) CH4 (3) H2O
(2) HCl (4) NH3 | 1 | draw them and the symmetrical one is nonpolar |