The great wall of China is the longest wall ever built. It is about 4,000 miles long and 26
feet tall.
Find its length in kilometers. 1 mi = 1.609km= 5280 ft.
Answer in units of km.

Asolution at 25 degrees celsius is 1.0 × 10–5 m h3o+. what is the concentration of oh– in this solution?

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Which statement correctly describes metallic bonds? a. they form when certain atoms lose electrons and other atoms gain electrons. b. they involve an attraction between anions and cations. they always involvpoth a metal and a nonmetal. d. they can only form between atoms of the same element. e. they form because electrons can move freely between atoms.