How do they know the valence of an element if they have never seen it?

the volume of a gas at 155 kPa changes from 22 liters to 10 liters what is the new pressure if the temperature remains constant

If a solution has virtually no hydrogen ions what type of pH does it have? 0 7 2 13

Which of the following statements is true about catalysts? and Why? a. Catalysts slow down the rate of chemical reactions b. All catalysts are enzymes c. Catalysts are used up during a chemical reaction d.

A reaction showing heat as a product is an exothermic reaction. TRUE FALSE

The protein keratin is composed of two helical strands that wrap around each other in what is called a coiled coil. The two strands remain in contact with each other over the entire length of the protein via hydrophobic interactions.

What is not needed for corrosion of metals? a. oxygen c. water b. ions d. sunlight

What force can move the oceans

How many moles of NO3 are there in 6.2g

Which compound will conduct electricity when it is dissolved in water? a. CH4 b. CuSO4 c. C6H6 d. C6H12O6

Peter is 5 ft, 11 inches tall. Paul is 176 cm tall. Who is taller?