Why is helium in group 18 on the periodic table though it only has 2 valence electrons?

Chemists can use moles to calculate: A. How much of the products are needed and how much reactant will be made. B. How much product will be made, but not how much of the reactants are needed. C.

The dissolution of barium hydroxide in water is an exothermic process. Which of the following statements is correct? A) The enthalpy of solid barium hydroxide plus pure water is less than that of the solution, at the same temperature.

Which of the following describes a scenario in which the molecular geometry would have the smallest bond angle (s) ?

When parallel light rays exit a convex lens, they.

Example 2: how many hydrogens are in c7h? n, which has 0 ring (s) and 2 double bond (s)

How can you use the chemical formulas for sucrose (C6H, 20,) and rust (Fe, O,) to classity them ionic or molecular compounds?

What is true of energy as is passes through an ecosystem? a. All of the energy in an organism is used by the animal that eats it. b. Any stored energy in an organism is used by the animal that eats it. c.

Which can associate a suspect and the firing of a gun? (its not b) A) markings on the gun's exterior B) markings on the casing C) markings on the bullet D) powder residues

Which of the following locations would most likely have the most fertile soul?

What is an "alloy" in the chapter of metals in chemistry?