Question

(02.02 lc)
______ is a nonmetal in the periodic table.
a mercury
b potassium
c sulfur
d yttrium
pregunta 7 (5 puntos)
(02.02 lc)
a neutral sodium atom has ______ electrons.
a 9
b 8
c 10
d 11
pregunta 8 (5 puntos)
(02.02 mc)
which of the following groups of elements are likely to have substances that have both metallic and non - metallic properties
a actinides
b group 18
c lanthanides
d group 14

Explanation:

1. Mercury is a metal and the only metal that is liquid at room - temperature. Potassium is an alkali metal. Yttrium is a transition metal. Sulfur is a non - metal, which is brittle, non - malleable, and a poor conductor of heat and electricity.
2. The atomic number of sodium is 11. In a neutral atom, the number of electrons is equal to the number of protons (which is the atomic number). So a neutral sodium atom has 11 electrons.
3. Group 14 elements have some elements with metallic and non - metallic properties. For example, carbon is a non - metal, silicon and germanium are metalloids (have both metallic and non - metallic properties), and tin and lead are metals. Actinides and Lanthanides are mostly metals. Group 18 elements are noble gases, which are non - metals.

Answer:

1. c. Sulfur
2. d. 11
3. d. Group 14