The symbol Ca-40 denotes that

A. a calcium atom contains 40 protons

B. a calcium atom contains 40 electrons

C. a calcium atom contains 40 neutrons

D. a calcium atom has a mass number of 40

What is the speed of a cheetah that travels 224 m in 8 Seconds

Is there a qualitative difference between the enthalpy of a phase transition versus the enthalpy of a heating or cooling process? If so, explain those differences.

32p is a radioactive isotope with a half-life of 14.3 days. if you currently have 38.1 g of 32p, how much 32p was present 9.00 days ago?

If you produce 14.5 g of O2 in the lab from a reaction that you showed by calculation could produce a maximum of 22.0 g of O2, what is your percent yield

What is the 27th element on the periodic table?

What is limiting reajent?

What elements react the most? Like have the most reactivity.

A neutral atom has an atomic number of 20 and a mass number of 42. How many electrons does the atom have?

A rock is placed into water and the volume of water increase 15ml. what is the density of the rock if it had a mass of 24.3 grams.

Suppose a student did not fully redissolve the Al (OH) 3 that initially formed upon the addition of H2SO4. Predict and explain how this would impact the apparent percent yield this student determines.