PLEASE HELP Which of the following statements is FALSE concerning the element silicon, Si?
A. Silicon has 4 valence electrons
B. Silicon is a metalloid
C. Silicon has a lower electronegativity than carbon
D. Silicon has the largest atomic radius in its group
The answer is not C or B.

Nitric oxide (no) can be formed from nitrogen, hydrogen and oxygen in two steps. in the first step, nitrogen and hydrogen react to form ammonia: n2(g) + 2 h_2(g) rightarrow 2 nh_3 (g) delta h = -92. kj in the second step, ammonia and oxygen react to form nitric oxide and water: 4 nh_3(g) + 5 o_2(g) rightarrow 4no(g) + 6 h_2o(g) delta h = -905. kj calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

Water (2510 g ) is heated until it just begins to boil. if the water absorbs 5.09×105 j of heat in the process, what was the initial temperature of the water?