Which of the following statements about stars is true?

All stars are the same age.

Stars vary greatly in age.

none of these

Stars rarely differ in age.

Which is more metallic a) Gold b) Bismuth

A car tire was inflated to 82.0 kPa in a repair shop where the temperature is 26.0C. What is the temperature of the gas in the tire if the pressure in the tire increases to 87.3 kPa when it is taken out of the repair shop?

What is the difference between an exothermic and endothermic reaction.

Which of the following is a property of a pure substance? A.) it can be chemically separated If it is a compound. B.) it's components can be separated with ease. C.) it is made up of two or more types of compounds. D.

Question 25 a chemist determined by measurements that 0.020 moles of mercury participated in a chemical reaction. calculate the mass of mercury that participated in the chemical reaction. round your answer to 2 significant digits.

When magnesium combines with oxygen, the reaction involves a. a conversion of protons into electrons. b. sharing of electrons between Mg and O. c. transfer of electrons from Mg to O. d. transfer of electrons from O to Mg.

The activation energy for the reaction no2 (g) + co (g) ⟶no (g) + co2 (g) is ea = 100 kj/mol and the change in enthalpy for the reaction is δh = - 375 kj/mol.

What process transform solar energy into chemical energy?

When the reaction was carried out the calculated theoretical yield for water was 176 grams but the measured yield was 148 grams what is the percent yield

For an atom's electrons, how many energy sublevels are present in the principal energy level n = 4?