Metals have high density. They are always solids at room temperature.
Metalloids have intermediate density. They are generally solids at room temperature.
Non-metals have low density. They can be solids, liquids or gases at room temperature.
Based on this, the <span>class of elements that includes all of the elements that are gases at room temperature is the non-metals</span>
Answer:
D) 5.15
Explanation:
Step 1: Write the equation for the dissociation of HCN
HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)
Step 2: Calculate [H⁺] at equilibrium
The percent of ionization (α%) is equal to the concentration of one ion at the equilibrium divided by the initial concentration of the acid times 100%.
α% = [H⁺]eq / [HCN]₀ × 100%
[H⁺]eq = α%/100% × [HCN]₀
[H⁺]eq = 0.0070%/100% × 0.10 M
[H⁺]eq = 7.0 × 10⁻⁶ M
Step 3: Calculate the pH
pH = -log [H⁺] = -log 7.0 × 10⁻⁶ = 5.15
The bonds in salt compounds are called ionic because they both have an electrical charge—the chloride ion is negatively charged and the sodium ion is positively charged.
Answer: 1 mole of H2O= about 1/3 of a cup (18 mL). It is helpful ... 6.02 x 1023 H2O molecules. = 6.02 x 1023 NaCl formula unit. 1 mole C. 1 mole H2O. 1 mole
Explanation:
