<span><em>Answer:</em>
A strontium-90 atom that has a lost two electrons has <u>38</u> protons, <u>52</u> neutrons, and <u>36</u> electrons.
<em>Explanation:
</em>Atomic number<em> of </em>Strontium (Sr) is 38.
<em>Atomic number = number of protons
</em>Hence, Strontium has 38 protons.
If the element is in neutral state,
number of protons = number of electrons.
Then, neutral Strontium atom should have 38 electrons.
But the question says Sr has lost 2 electrons. Hence, number of electrons should be 38 - 2 = 36.
Mass number = number of protons + number of neutrons.
The given mass number is 90. Hence, number of neutrons should be 90 - 38 = 52.</span>
Supposing a temperature of 25 degrees and supposing that all
activity coefficients are 1
pH = -log[H+]
pOH = -log[OH-]
pH + pOH = 14
Thus a pH of 2.50 would mean that the [H+], the concentration of the hydrogen
ion, would be 10^(-2.50)
pH + pOH = 14
pOH = 14 - pH = 14 - 2.5 = 11.5
MOH- levels would be coordinated with pOH
pOH = -log[OH-] ==> [OH-] = [MOH-] = 10^-pOH = 10^-11.5 = 3.2 x 10^-12
Therefore, MOH¯ = 3.2 × 10¯12 M
Answer: 23.8889
Explanation:
(75°F − 32) × 5/9 = 23.889°C
Answer:
1.8 x 10⁻⁵
Explanation:
NH3(aq) + H2O(l) ⇄ NH4⁺(aq) + OH⁻(aq)
I 0.95 0 0
C -x +x +x
E 0.95-x x x
Kb= [NH₄⁺] [OH⁻] / ( NH₃) = x²/ (0.95-x )
P(OH) = 14-PH = 14-11.612 = 2.388
(OH)⁻¹ = 10⁻²°³⁸⁸ = 4.09 x 10⁻³ = x
Kb = (4.09 x 10⁻³)²/ (0.95-4.09 x 10⁻³)
= 1.8 x 10⁻⁵
