The reaction of 2h2+o2-->2H2o + heat is

A exothermic

B catalyze

C liquid reaction

D endothermic

E none

Is 2.86 atm of pressure more of less than 2000 mm of Hg

Use your knowledge of the periodic table and the periodic table provided. Which pair of elements are more similar chemically Na and Mg or F and Br? And why? A) F and Br, because they are in the same group.

Elements are different because their atoms contain different numbers of

Which best represents the reaction of calcium and zinc carbonate (ZnCO3) to form calcium carbonate (CaCO3) and zinc? O Ca-ZnCO3 + CaCO3 - Zn O Ca + ZnCO3 → CaCO3 + Zn O CaCO3 + Zn → Ca + ZnCO3 O CaCO3 + Zn + Ca - ZnCO3

If the temperature of a piece of steel decreases, what happens to its density

A 0.500-L sample of H₂SO₄ solution was analyzed by taking a 100.0mL aliquot and adding mL of. After the reaction occurred, an excess of ions remained in the solution. The excess base required mL of for neutralization.

Ammonia can be prepared by the reaction of magnesium nitride with water. The products are ammonia and magnesium hydroxide. Write and balance the equation.

Which period is the shortest in the long form of the periodic table? Name all the elements in this period.

A mole of gas at 0.0oC and 760. torr occupies 22.4 L. What is the volume of this gas at 25. oC and 760. torr

Is a nylon string conductor or insulator