Give the number of significant figures indicated.

0.066

A. 3

B. 0

C. 1

D. 2

Is methylene chloride more or less dense than water?

The air in a hot-air balloon at 735 torr is heated from 22.0°C to 46.0°C. Assuming that the moles of air and the pressure remain constant, what is the density of the air at each temperature? (The average molar mass of air is 29.0 g/mol.)

Calcium reacts with hydrochloric acid, HCI, to make calcium chloride and hydrogen gas (H2). 1) write a word equation for this reaction. 2) write a balanced symbol equation for this reaction.

Which sample contains the greater number of atoms, a sample of Li that contains 6.8 x 10^22 atoms or a 1.97 mole sample of Na?

Methane combines with oxygen in the air to make carbon dioxide and water vapor. Which of the chemical equations matches the reaction above? A. CH4 + 2O2 CO2 + 2H2O B. C2H4 + 2O2 2CO + 2H2O C. CH4 + 2CO2 2CO2 + 2H2O D. CH4 + 2O 2CO + 2H2O

How are electromagnetic different than all other waves

Find the ratio of speeds of an electron and a negative hydrogen ion (one having an extra electron) accelerated through the same voltage, assuming non-relativistic final speeds. Take the mass of the hydrogen ion to be 1.67*10^{-27} kg.

A type of rock that undergoes changes because of heat and pressure

How many milliliters of a 1.25 molar HCL solution would be needed to react completely with 60 g of calcium metal Ca+2HCl - - > CaCl2 + H2

What mass of copper is required to replace silver from 4. oog ogre silver nitrate dissolved in water