How many helium atoms are in a helium blimp containing 498 kg of helium?

Centerville has a population of 10,000 people. The town is currently experiencing a severe drought. The city council has decided to require all toilets to be fitted with a device that causes it to use 1.

On a hot day, the sun causes the sidewalk to become very warm. How do the particles that make up the sidewalk change as the temperature increases? A:They move closer together. B:They move freely from place to place. C:Their kinetic energy decreases.

Why is pure acetic acid often called glacial acetic acid? (A) Because it freezes just below 0°C, forming white crystals. (B) Because it freezes just below 100°C, forming white crystals.

A chemist is using a solution of HNO3 that has a pH of 3.75. What is [H+] for the solution?

Write the net ionic equation for the following molecular equation Mg (s) + Snso (aq) Mgso4 (aq) Sn (s) Use the lowest possible coefficients. Use the pull-down boxes to specify states such as (aa) or (s). If a box is not needed, leave it blank.)

Butane - ethane - methane - propane: What do these hydrocarbons have in common? A) The same number of carbons present. B) They all have polar covalent bonds. C) They all have single covalent bonds. D) They have the same structural formulas.

Identify the form of energy that is converted into ther - mal energy by your body

Determine the number of moles of sulfur trioxide produced when 3.5 moles of oxygen gas is consumed in the reaction

For each of the following balanced oxidation-reduction reactions, (i) identify the oxidation numbers for all the elements in the reactants and products and (ii) state the total number of electrons transferred in each reaction. 1.

Hypervitaminosis is a serious health threat associated with excessive amounts of ingested fat-soluble vitamins. why do water-soluble vitamins not commonly pose the same threat?