How many atoms are present in 3 molecules of chromium

A 5.45-g combustible sample is burned in a calorimeter. the heat generated changes the temperature of 555 g of water from 20.5°c to 39.5°c. how much energy is released by the burning? the specific heat of water is 4.18 j / (°c * g).

A steam power plant produces 500 MW of electricity with an overall thermal efficiency of 35%. Determine (a) the rate at which heat is supplied to the boiler and (b) the waste heat that is rejected by the plant.

Most cancer-causing air pollutants are found outdoors. True False

H20 consists of polar molecules. CO2 consist of no polar molecules. How do chemist explain this difference?

A 10 kg mass rests on a table. What acceleration will be generated when a force of 5 N is applied? a 0.5 m/s2 b 3.5 m/s2 c 5 m/s2 d 35 m/s2

Why do the densities of most substances decrease with an increase in temperature?

Consider two planets in space that gravitationally attract each other if the mass of one of them stays the same and the mass of the other is doubled AND the distance between them is doubled, then the force between them changes by what factor? A.

David delivers meals to elderly people once a week. He uses a cart to move the meals. The cart has four smooth wheels. Which type of friction acts between the cart wheels and the sidewalk? A. sliding friction B. rolling friction C. fluid friction D.

Current flows through a resistor; (a) with no direction since it is not a vector (b) from any potential to any different potential (c) from high potential to low potential (d) from low potential to high potential (e) cannot be determined

A concave mirror has a focal length of 11 cm. What is its radius of curvature?