An element has an atomic number of 30. How many protons and electrons are in a neutral atom of the element?

A. 30 protons, 30 electrons

B. 15 protons, 15 electrons

C. 60 protons, 30 electrons

D. 30 protons, 0 electrons

How does chemical energy hold molecules together?

Describe one technology used to travel to space and one technology used to return from space

Which of the following is the best piece of laboratory glassware for preparing 500.0 mL of an aqueous solution of a solid? (A) Volumetric flask (B) Erlenmeyer flask (C) Test tube (D) Graduated beaker (E) Graduated cylinder

For heavy elements what is the ratio of neutrons to protons that predicts a stable nucleus?

What happens when an acid is added to pure water?

A college student driving to classes produces 8000 kg of carbon dioxide (CO2) in a year, contributing to global warming. What volume of CO2 is produced? (The density of carbon dioxide is 2.0 g/L.)

For the first five steps of glycolysis, the appropriate sequence of enzymes is: A. phosphofructokinase-1 (PFK-1). B. hexokinase / glucokinase. C. fructose bisphosphate aldolase. D. Phosphoglucoisomerase. E. triose phosphate isomerase (TPI). a.

2NO + O2 → 2NO2 What type of chemical reaction is shown above? a combustion reaction b double displacement C synthesis d decomposition e single displacement

Why did Bromophenal solutions change from yellow to blue (what chemical reaction happended) ?

How many milliliters of calcium, with a density of 1.55 g/mL, are needed to produce 85.8 grams of calcium fluoride in the single replacement reaction below? Show all steps of your calculation as well as the final answer.