Susan should follow PEMDAS,
Parentheses
Exponents
Multiplication
Division
Addition
Subtraction,
So, the first step should be, to solve the equation in the parentheses.
I hope this helps!
Density = m/v therefore v = m/d v = 25/0.85 v = 29.4117... cm^3 ( = 2.94 * 10^-5 m^3
A, radium-228. Alpha radiation is essentially just two protons and two neutrons leaving the atom, causing the atomic number to drop by two (since the protons left) and the mass number to drop by four (since two neutrons and protons left).
I remember coming across this question and the options were:
KOH, HCN, NH₃, HI, Sr(OH)₂
Now, a substance with a low pH is one that dissociates completely in water to release hydrogen ions, while basic substances dissociate completely to release hydroxide ions. Therefore, in the order of increasing pH:
HI, HCN, NH₃, Sr(OH)₂, KOH
Answer:
211.63 g.
Explanation:
- Particles could refer to atoms, molecules, formula units.
- <em>Knowing that every one mole of a substance contains Avogadro's no. of molecules (NA = 6.022 x 10²³).</em>
<em><u>Using cross multiplication: </u></em>
1.0 mole → 6.022 x 10²³ molecules.
??? mole → 8.95 x 10²³ molecules.
- The no. of moles of magnesium acetate = (8.95 x 10²³ molecules) (1.0 mole) / (6.022 x 10²³ molecules) = 1.486 mol.
∴ The grams of magnesium acetate are in 8.95 x 10²³ formula units = n x molar mass = (1.486 mol)(142.394 g/mol) = 211.63 g.
