Answer: Strontium has 219 pm
Iodine has 115 pm
Explanation: So the answer is Sr-Strontium
D. Marble caused by heat and lots of pressure.
Primary succession occurs following an opening of a pristine habitat, for example, a lava flow, an area left from retreated glacier, or abandoned strip mine. In contrast, secondary succession is a response to a disturbance, for example, forest fire, tsunami, flood, or an abandoned field
Answer:
The pH of a solution containing an amphetamine (with pKb of 4.2) concentration of 250 mg/l is 10.5
Explanation:
To solve the question we note that the
The mass of amphetamine = 250 mg/l
The molar mass of amphetamine = 135.2062 g/mol
Number of moles of amphetamine = (250 mg)/(135.2062 g/mol) = 1.85×10⁻³ moles
That is the initial concentration of amphetamine = 1.85×10⁻³ M
We have
therefore
Which gives 6.3×10⁻⁵
x = 0.0003116 = [OH⁻] = [C₉H₁₃NH⁺]
However x = [OH⁻] = 3.116×10⁻⁴
pOH = -log[OH⁻] = -log(3.116×10⁻⁴) = 3.506
pH = 14 - pOH
= 14 - 3.506
= 10.49
≈ 10.5
C. Im gonna say Proteins but I am not completely sure.