Calcium's atomic number is 20. it forms ions with 18 electrons. what is the electrical charge of a calcium ion?

What procedure do scientists use to make new discoveries?

Consider the reaction 2 nh3 + ch3oh → products. how much nh3 is needed to react exactly with 21 grams of ch3oh?

A hot air balloon is filled with 15 moles helium gas and 5 moles nitrogen gas. What is the volume of the balloon at 1.01 atm and 300 K?

Acetylene (c2h2) undergoes combustion in excess oxygen to generate gaseous carbon dioxide and water. given δh°f[co2 (g) ] = - 393.5 kj/mol, δh°f[h2o (g) ] = - 241.8 kj/mol, and δh°f[c2h2 (g) ] = 226.6 kj/mol, how much energy is released (kj) when 10.

Description of precipitation

In a water solution, HCl and NaOH react to form H2O and NaCl. Radium-226 undergoes alpha decay to form radon-222. The temperature of both of these reactions is increased.

Which of these statements is true about endothermic reactions, but not about exothermic reactions? The reactants and products are different substances. The reactants have less energy than the products. The temperature of the container increases.

Calculate H3O + when OH - is 2*10 - 8

An element and an atom are different but related because a) A particular element is made up of many different types of atoms b) A molecule is the same as an atom c) An element is made up of all the same type of atom d) An element is smaller than an

Calculate the rate speed per drop in minute when applying a drip of 1000mg to last 4 2 hours