What is the most used element in the periodic table? what are its uses?

Which of the following is true about compounds? 1) They can be physically separated into their component elements. 2) They have properties similar to those of their component elements. 3) They have compositions that vary. 4) They are substances.

When chromium chloride crcl2 is dissolved in water the temperature of the water decreases answers?

What is the pressure of a gas that began at 38 torr, and 500L and is changed to occupy a volume of 677 L?

A car traveled at a constant velocity of 70 mph from noon to 2:00 pm. At 3:00 pm the velocity of the car was 80 mph; and finally at 4:30 pm the velocity of the car was 40 mph.

Is making salt water a physical or chemical

Sea water, a solution composed of a variety of salts dissolved in water. the salt is the

Which equation using element symbols correctly describes the reaction: "One molecule of methane plus two molecules of diatomic oxygen react to form two molecules of water and one molecule of carbon dioxide?" A. CH4+2O2+2H2O→CO2 B. 2H2O+CO2→CH4+2O2 C.

Which of the following happens during a new moon? More than half of the moon is visible from Earth. Less than half of the moon is visible from Earth. The illuminated half of the moon faces towards Earth.

Which statement about Niels Bohr's atomic model is true? Higher orbits have lower energies. Each orbit has a specific energy level. Electrons can exist in any energy level. Orbits close to the nucleus have no energy.

How do mixtures differ from pure substances?