1) B+3 is ok. The exercise already put B+3. What
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2) Ge is a neutral atom because it doesn't have any charge.
Germanium has 32 electrons and 32 protons because its atomic number is 32.
Be careful with that.
Neutral atoms have the same numbers of electrons and protons.
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3)
Answer:
Part A: 36 MBq; Part B: 18 MBq
Explanation:
The half-life is the time it takes for half the substance to disappear.
The activity decreases by half every half-life
A =Ao(½)^n, where n is the number of half-lives.
Part A
3.0 da = 1 half-life
A = Ao(½) = ½ × 72 MBq = 36 MBq
Part B
6.0 da = 2 half-lives
A = Ao(½)^2 = ¼ × 72 MBq = 18 MBq
Each mole of Ca(OH)₂ will produce 2 moles of OH- ions
Each mole of OH- ions will require one mole of H+ ions
Thus,
moles of OH- ions = moles of H+ ions = 2 x 0.3
moles of H+ ions required = 0.6
Each mole of HCl will produce one mole of H+ ions
Moles of HCl = moles of H+ ions
Moles of HCl = 0.6
The concentration of the hydroxide ions after 50 ml of 0.250M NaOH is added to 120ml of 0.200M Na2SO4 is 7.35 x 10^-2 M.
What is meant by concentration?
Concentration is the total amount of solute present in the given volume of solution. this is expressed in terms of molarity, molality, mole fraction, normality etc. The term concentration mostly refers to the solvents and solutes present in the solution.
Concentration of hydroxide ions can be calculated by,
M (OH^-) = V (NaOH) x M (NaOH) / V (total) = 50ml x 0.250M / 50ml + 120ml = 0.0735M = 7.35 x 10^-2 M.
where M (OH^-) = concentration of hydroxide ions, V(NaOH) = volume of NaOH, M(NaOH) = concentration of NaOH.
Therefore, the concentration of the hydroxide ions after 50 ml of 0.250M NaOH is added to 120ml of 0.200M Na2SO4 is 7.35 x 10^-2 M.
To learn more about concentration click on the given link brainly.com/question/17206790
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