Answer: Would be D. Fe and S have an ionic bond, while S and O have covalent.
Hope that helps.
When we convert the given mass in grams and volume in liters to m/v percent, we recall that m/v percent is expressed as grams/100 milliliters. In this case the expression becomes (50 grams/ 2500 L)*(0.1L/100ml), that is equal to 0.002 grams/ 100 mL. Hence the the concentration is equal to 0.2 m/v percent.
The correct answer is B. on Apex!
Frequency, f = v / λ
f = 2.998 * 10⁸ / 3.55*10⁻⁸
f = 8.445 * 10¹⁵ Hz.
Letter d, because they are both alkali metals (group one)
