Which element is located in period 4? Silicon (SI)
Iron (Fe)
Beryllium (Be) Zirconium (Zr)

Joseph has hypothesized that sound travels in waves. if he were following the scientific method, what should he do next? a. ask a question. b. test the hypothesis. c. study the results. d. tell other scientists about his hypothesis.

Cucl2 + 2nano3 cu(no3)2 + 2nacl what is the percent yield of nacl if 31.0 g of cucl2 reacts with excess nano3 to produce 21.2 g of nacl? 49.7% 58.4% 63.6% 78.7%

A50.0g sample of liquid water at 0.0 c ends up as ice at -20.0 c. how much energy is involved in this change?