If the atomic number is 3 and the mass number is 7 what is the number of protons

Looking across period 4 of the periodic table, potassium (atomic number 19) is followed by calcium (atomic number 20), which is followed by scandium (atomic number 21). Which element should have the largest atomic radius?

Solid sodium hydroxide decomposes into solid sodium oxide and gaseous water. Write a balanced chemical equation for this reaction.

A solid mass of 25g is added to a solution with the mass of 60g. The final mass of the solution is 75g. Explain why the mass of the products does not equal combined reactant mass

How does increased pressures result in the formation of minerals

What are some applications of the field of spectroscopy?

When does raising the temperature of a gas increase its pressure? A. temperature B. volume C. number of particles D. pressure

Hexyne. What does the name of this hydrocarbon tell you about its molecular structure?

Which of the following processes includes all of the others? Group of answer choices transport of an ion down its electrochemical gradient osmosis passive transport facilitated diffusion

How is the Bohr atomic model different from the plum-pudding model? A. In Bohr's model, the atom's mass is found at its center instead of distributed throughout. B. In Bohr's model, the atom's mass is mostly made up of electrons instead of protons.

What does the cell theory state? A. that cells come from other cells B. that cells come only from animals C. that cells cannot be created or destroyed