At the same temperature, a freshwater lake frezzes but a salt water bay does not because

Which statement describes a change that occurs during a chemical reaction? A. Atoms in the original substances are changed into different atoms to make new substances. B.

which statement accurately summarizes the law of conservation of energy? energy in the universe is always changing in quantity. energy can change from one type to another. energy can be created or destroyed.

Calculate the number of moles of the indicated sub - stance in each of the following samples. a. 41.5 g of MgCl2 b. 135 mg of Li2O c. 1.21 kg of Cr d. 62.5 g of H2SO4 e. 42.7 g of C6H6 f. 135 g of H2O2

Which has the larger mass 1 cm of copper 1cm aluminum 1 cm

Which elements can react to produce a molecular compound? (1) calcium and chlorine (2) hydrogen and sulfur (3) lithium and fluorine (4) magnesium and oxygen

Which statement about the noble gases is most reliable? The chemistry of the reactions of noble gases is not very interesting. The noble gases are some of the most beautiful elements. The noble gases are in the rightmost column of the periodic table.

The gases inside of a normal tire are usually measured when they are at ambient standard temperature (298 K) & under a controlled pressure of 32.

What is the equivalent mass of HBr in a complete neutralization reaction?

Coal can be converted to methane gas by a process called coal gasification. The equation for the reaction is the following: 2 C (s) 2 H2O (l) - -> CH4 (g) CO2 (g) What mass in grams of carbon is required to react with water to form 1.00 mol CH4

When more than one variable in an experiment is changed at a time, the scientist A. cannot tell which change produced the results. B. cannot accurately measure both variables at the same time. C.