Why is gas collected over water not pure

What has56 protons and 54 electrons and 74 neutrons

What element has a molar mass of 30.974 g/mol

The isotope 239 Pu 94 has a half life of 24,400 years. If a sample of nuclear waste originally contained 12kg of 239 Pu 94, how much time must pass before the amount falls to 3 kg?

A gas occupies 100 liters at 30 degrees C under a pressure of 1.28 atm. Approximately what volume would the gas occupy at STP (273 K, 1 atm) ?

Sulfur dioxide gas, SO2 (g), is released from active volcanoes. It reacts in the atmosphere to form sulfur trioxide, SO3 (g). 2SO2 (g) + O2 (g) → 2SO3 (g) Which statement (s) best describes the reaction? Check all that apply.

Why does the sun appear to be the brightest star in the sky? A - Its apparent brightness is much greater than other stars. B - It burns more gas, making it brighter than any other star.

What effect does nuclear radiation have on atoms? It splits atoms. It burns atoms. It ionizes atoms.

The density of an aqueous solution of nitric acid is 1.36 g/ml and the concentration is 2.48 m. what is the concentration of this solution in percent by mass?

In a crystal lattice of an ionic compound, A. Kind of a given charge are clustered together B. Ions are surrounded by ions of the opposite charge C. A sea of electrons surrounds the ions D. Neutral molecules are present

Discuss why two objects of made of the same type of matter at the same starting temperature with different masses increase in temperature at different rates when the same amount of thermal energy is transferred to each object.