What effect to calcium ions have on the water in ecosystems?

A. they add to its hardness

B. they increase its acidity

C. they reduce its pH

D. they decrease its salinity

Gasoline has a density of 0.69g/cm cubed. Calculate the mass of a litre of gasoline.

A rigid, 2.50 L bottle contains 0.458 mol He. The pressure of the gas inside the bottle is 1.83 atm. If 0.713 mol Ar is added to the bottle and the pressure increases to 2.

What is the definition - deka?

HBr + H₂SO₄ SO₂ + Br₂ + H₂O Did H change oxidation number?

The September 11th attacks were later linked to A. Hamas. B. al-Qaeda. C. Hezbollah. D. Saddam Hussei

What is true of an acidic solution at room temperature?

Why does a higher concentration make a reaction faster? There are more collisions per second and the collisions are of greater energy. Collisions occur with greater energy. There are more collisions per second.

A property of metals is high thermal conductivity which is

Do exorthermic reactions make surrounding hotter?

What's a certain indicator that a molecule is polar?