Which changes are evidence of a chemical reaction? a beaker of water becomes hot to the touch upon?

Match each element to the number of electrons in its valence shell Term Definition Beryllium (Be) A) Two Carbon (C) B) One Lithium (Li) C) Four Boron (B) D) Three The order above is wrong, match them correctly.

According to Charles's Law, what happens to the volume of a gas when temperature decreases? Assume the gas is at constant pressure. a. It is constant c. It increases b. It decreases d. None of the above

Identify the major force between molecules of pentane. dispersion dipole-dipole hydrogen bonding ion-dipole ion-ion

Define "aldose" and "ketone" and recognize them structurally

Iodine is prepared both in the laboratory and commercially by adding Cl 2 (g) Cl2 (g) to an aqueous solution containing sodium iodide.

A vertical piston-cylinder device contains water and is being heated. During the heating process, 70 kJ of heat is transferred to the water, and heat losses from the side walls amount to 8 kJ.

Which of the following functions occurs in the part of the digestive system indicated by the arrow? Secretion of buffers and digestive enzymesAcid breakdown of swallowed foodsSecretion of bile and buffersAbsorption of water and ions

Sodium metal and water react to create sodium hydrogen and hydrogen gas through the unbalanced equation. Na + H20 - NaOH H2 By determining the limiting reactant, calculate the theoretical yield of hydrogen gas (in grams) if 79.

1) Mg (s) + 2 H + (aq) - --> Mg2 + (aq) + H2 (g)  H°12) Mg2 + (aq) + H2O (l) - --> MgO (s) + 2 H + (aq)  H°23) H2 (g) + 1/2 O2 (g) - --> H2O (l)  H°34) Mg (s) + 1/2 O2 (g) - --> MgO (s)  H°4

A substance has a solubility of 350 ppm. how many grams of the substance are present in 1.0l of a saturated solution