As far as I can tell the best answer for this would be (A) Neon. However, I would argue that this is at the very least a misleading question. Atoms are less identified by their electrons than their protons (which is represented always by its atomic number). Although atoms can gain or lose electrons, the protons would never change (and remain the same element). Personally, I would have written the question as, "When Magnesium loses its valence electrons, its new number of electrons would most closely resemble _____"
<span>The nucleus is the organelle present in eukaryotic cells with the main function in the control of all cell activities and maintaining the gene integrity. Namely, it contains the genetic material of the cell in the form of chromosomes (DNA molecules in complex with proteins). It is enclosed by the nuclear membrane which regulates the movement of proteins and RNA in and out of the nucleus.</span>
Here you are! I hope it helps, and also for the ones I put a red ‘x’ it depends on how you round it.
Answer:
13.20
Explanation:
Step 1: Calculate the moles of Ba(OH)₂
The molar mass of Ba(OH)₂ is 171.34 g/mol.
0.797 g × 1 mol/171.34 g = 4.65 × 10⁻³ mol
Step 2: Calculate the molar concentration of Ba(OH)₂
Molarity is equal to the moles of solute divided by the liters of solution.
[Ba(OH)₂] = 4.65 × 10⁻³ mol/60 × 10⁻³ L = 0.078 M
Step 3: Calculate [OH⁻]
Ba(OH)₂ is a strong base according to the following equation.
Ba(OH)₂ ⇒ Ba²⁺ + 2 OH⁻
The concentration of OH⁻ is 2/1 × 0.078 M = 0.16 M
Step 4: Calculate the pOH
pOH = -log OH⁻ = -log 0.16 = 0.80
Step 5: Calculate the pH
We will use the following expression.
pH + pOH = 14
pH = 14 - 0.80 = 13.20