ions are ions composed of two or more covalently bonded atoms.

please help :'(

Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? a. magnesium has a 2- oxidation number and chlorine has a 1+ oxidation number. b. magnesium has a 2- oxidation number and chlorine has a 2+ oxidation number. c. magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number. d. magnesium has a 1+ oxidation number and chlorine has a 1- oxidation number.

Apiece of metal with a length of 1.42 cm was measured using four different instruments. which of the following measurements is the most accurate?

What does the symbol (–hfus) indicate in a phase change?