Which set of values represents standard pressure and standard temperature

When the temperature of a hollow sphere with 685 L (volume) of helium gas is held at 621 K (temp), the pressure of the gas is 1890 kPa. How many moles of the helium does the sphere contain?

Consider the group 1A elements sodium (period 3), potassium (period 4), and rubidium (period 5). What would you predict about the ionization energies of these elements?

If you walk for 1 1/2 hours at an average speed of 4 miles/h. How far will you have walked?

When baking soda (sodium bicarbonate or sodium hydrogen carbonate, NaHCO3) is heated, it releases carbon dioxide gas, which is responsible for the rising of cookies, donuts, and bread.

Many industrial reactions, like the reaction of nitrogen gas (N2) and hydrogen gas (H2) to produce ammonia for fertilizers, have a very slow reaction rate. What is one method that would speed up this reaction? A.

What will an atom do if it has 1 to 3 valence electrons

What is milk best described as? solution, suspension, compound, or colloid?

In any chemical reaction, the quantities that are conserved are ... A. mass and moles. B. the number of molecules and the volumes. C. the number of moles and the volumes. D. mass and number of atoms.

How many neutrons does element X have if its atomic number is 39 and its mass number is 75?

Enter a chemical equation for LiOH (aq) LiOH (aq) showing how it is an acid or a base according to the Arrhenius definition. Consider that strong acids and bases dissociate completely. Express your answer as a chemical equation.