One radioactive isotope of calcium has an atomic mass of 47. How many protons are in this calcium-47 nucleus? A) 17 B) 20 C) 27 D) 47

Given the reaction: 4NH3 + 3O2 → 2N2 + 6H2O. How many moles of N2 are produced when 1.0 mole of NH3 is consumed?

1. Describe the universal gravitational law.

The density of a planet is 0.69 g/cm3 (density of water is 1.0 g/cm3). Which of the following planets might this be? A. Mercury B. Venus C. Saturn D. Mars

What are two different kinds of rock that are easily weathered by carbonic acid?

Ammonium perchlorate nh4clo4 is the solid rocket fuel used by the u. s. space shuttle. it reacts with itself to produce nitrogen gas n2, chlorine gas cl2, oxygen gas o2, water h2o, and a great deal of energy.

Assuming that air contains 78 percent N2, 21 percent O2 and 1 percent Ar, all by volume. How many molecules of each type of gas are present in 1.0 L of air at STP?

Two children are playing tag. Child A who is doing the chasing can run 100m in 24 seconds Child B is running away from child A and can run 64m in 21 seconds.

What ion does a base increase

What is the definition of Amplitude?

An excess of NiCO3, 12 g, was added to 40cm cube of sulpheric acid, 2.0 mol/dm cube. The unreacted nickel carbonate was filtered out and the filtrate evaporated to optain the crystals.