What number should be placed in the blank to balance the equation 4fe + __O2 = 2Fe2O3

A cylinder contains 250 g of Helium at 200 K. The external pressure is constant at 1 atm. The temperature of the system is raised by 74 K. Calculate the heat lost or gained by the system.

What is the percent composition of nitrogen in Ca (NO3) 2?

What do infraded technologies fiber optic technology and satellite technology is all have in common?

What is kinetic energy? A. the energy an object has due to its motion B. the energy derived from chemical reactions C. the energy an object has due to its position D. the energy an object releases as heat

7. Convert 158 g of C to moles.

Which kind of dating can be used to determine the exact age of the rock and which kind of carbon dating is used to compare the ages of rocks?

Calculate the density of an object with a mass of 30g and volume of 6cm^3

What happens when light from the sun passes through any type of matter? the light slows down. the light speeds up. most of the light is absorbed. most of the light is reflected.

What is the chemical name for Fe (HCO3) 2

How are protons, electrons, and neutrons correctly compared