Which of the following are combustion reactions? NaNO3 (aq) arrow Na+(aq) + NO3-(aq)

C2H6 (g) + O2 (g) arrow CO2 (g) + H2O (l)

Mg(s) + HCl (aq) arrow H2 (g) + MgCl2 (aq)

HCl (aq) + NaOH (aq) arrow HOH (l) + NaCl (s)

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

Select the word from the list that best fits the definition the nuclear family into which a person is born or adopted.

Water undergoes a large change in density at 0 ∘ c as it freezes to form ice. calculate the percent change in density that occurs when liquid water freezes to ice at 0 ∘ c given that