Identify the following as a compound or a mixture: quartz (SiO2)

What is the term for the number of protons in the nucleus of each atom of an element? it also indicates the number of electrons in the atom?

Do moving electrons have a magnetic field?

Which of the following is a decomposition reaction? A. 2Mg+O2 - > 2MgO B. CH4+2O2 - > CO2+H2 C. 2H2O + 2Na - > 2NaOH+H2 D. CaCO3 - >CaO+CO2

Garfield (weighing 24 lbs) took a flight to the moon on the space shuttle. As usual, he stuffed himself with lasagna during the entire flight and napped when he wasn't eating.

The atomic weight of silver is 107.868 amu. Naturally occurring silver consists of two isotopes. 107Ag (mass = 106.904 amu) and 109Ag (mass = 108.905 amu). What percentage of naturally occurring silver is the heavier isotope? a. 45.4% b. 52.6% c. 62.

A flask containing 155cm^3 of hydrogen was collected under a pressure of 22.5kPa. What pressure would have been required in order for the volume of the gas to have been 90.0 cm^3 at constant temperature?

Which change is most likely to occur when a molecule of H2 and a molecule of I2 collide with proper orientation and sufficient energy? 1. a chemical change, because a compound is formed 2. a chemical change, because an element is formed 3.

Which substance is a diatomic molecule? a. he b. o2 c. co2 d. h2o?

What is the difference between the electronegativity values of sodium and bromine?

Which of the following elements is the most stable element? argon, manganese, phosphorus, robidium