Which of the following terms best describes the nucleus of a radioactive element?

a. unchanging

b. explosive

c. unstable

d. energized

How to balance the chemical equation of Al (S) + CuO (S) >Al2O3 (S) + Cu (S)

A steel cylinder containing 25 kg of CCl2F2 in the form of liquid and vapor is set outdoors on a warm day 25 degrees celsius. What is the approximate pressure of the vapor in the cylinder?

You and a friend each decide to build the same model airplane. After the airplanes are built, you decide to conduct an investigation to determine which airplane can glide through air the longest. Outline a plan to conduct your investigation.

Biologists study the structural adaptations of organisms, which are

What condition must be met for a battery to be rechargeable? A. Either its anode or its cathode must generate a gas as a result of the electrochemical reaction. B.

Sulfur (S) has 16 protons and 16 neutrons. How many electron shells does an element of sulfur have?

Which one of the following statements about orbital energies is incorrect? A) The energy of a given orbital increases as the nuclear charge Z increases. B) In many-electron atoms the energy of an orbital depends on both n and l.

When solid lead (II) sulfide ore burns in oxygen gas, the products are solid lead (II) oxide and sulfur dioxide gas.? A. write the balanced equation B. how many grams of oxygen are required to react with 29.9 grams of lead II sulfide? C.

What are some differences between insect larvae and worms?

Suppose that 100 grams of water at 50.0°C is placed in contact with 200 grams of iron at 30.0°C. The final temperature is 46.5°C. The specific heats of water and iron respectively, are 4.18 and 0.45 joules per gram times Celsius.