Which of these is a demonstration of a chemical change? A. ice melting into water B. wood becomes charred and black from burning C. water evaporates from a sugar solution, leaving behind sugar crystals D. a balloon suddenly popping

From what names do some chemical symbols come from

Which combination of atoms can form a polar covalent bond?

The density of water is 1.00 g/mL. If you're swimming pool holds 208,000 gallons of water, what is the weight of the water in a field swimming pool in tons? (1 ton = 2000lb).

Select true or false: if the ph of pure water is 7.0, the hydroxide ion concentration in pure water is 1 * 10-7 m.

Why do Beryllium and fluorine combine in a 1:2 ratio?

Benzene, C6H8, has an enthalpy of fusion = 10.19 kJ/mol. Calculate the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?

What is the H3O + ion concentration of a solution that has an OH - ion concentration of 1.0 * 10^-3M? A) 1.0 * 10^-3M B) 1.0 * 10^-7M C) 1.0 * 10^-11M D) 1.0 * 10^-14M

Given the following chemical reaction: 2 O2 + CH4 CO2 + 2 H2O In the reaction of 6 moles of CH4 with excess oxygen, how many moles of water could be produced? 6 C 12.01 Carbon 1 H 1.01 Hydrogen 8 O 16.00 Oxygen A. 4 B. 6 C. 8 D. 12

Most mutagens have what kind of an effect on an organism?

According to the hess's law, the enthalpy of solution is: δhsoln = δhsolute + δhsolvent + δhmix. considering dissolving a small drop of nonpolar pentane oil in water which term (s) in the equation will experience the largest enthalpy change.