The noble gases are helium, neon, argon, krypton, xenon, radon, and ununoctium. The noble gases are relatively nonreactive. This is because they have a completevalence shell<span>. They have little tendency to </span>gain<span> or lose </span>electrons. <span>These gases all have similar properties under standard conditions: they are all odorless, colorless, monatomic gases with very low chemical </span>reactivity<span>. The six noble gases that occur naturally are helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).</span>
Rust on a nail is a chemical change.
Ice melting IS a physical change. Ice is made of water, when you melt ice its still water. Just in a different physical state.
Yes your choices of B C D are right
Formula: molality, m = n solute / kg solvent
n solute = # of moles of solute = mass(g) / molar mass
Molar mass of Mg Br2 = 184.11 g/mol
m = [46g / 184.11 g/mol] / 0.5 kg = 0.50 mol/kg
