They are arranged in shells
Answer:
6.02 x 10²³ atoms
Explanation:
Given parameters:
Number of moles CaSO₄ = 1 mole
Unknown:
Number of Ca atoms in the given compound = ?
Solution:
The given compound is:
CaSO₄
1 mole of CaSO₄ is made up of 1 mole of Ca atoms
Now;
1 mole of any substance contains 6.02 x 10²³ atoms
1 mole of Ca atoms will also contain 6.02 x 10²³ atoms
The volume of 10 grams of frozen water is more than the volume of 10 grams of liquid water
Answer:
6.88 mg
Explanation:
Step 1: Calculate the mass of ³²P in 175 mg of Na₃³²PO₄
The mass ratio of Na₃³²PO₄ to ³²P is 148.91:31.97.
175 mg g Na₃³²PO₄ × 31.97 g ³²P/148.91 g Na₃³²PO₄ = 37.6 mg ³²P
Step 2: Calculate the rate constant for the decay of ³²P
The half-life (t1/2) is 14.3 days. We can calculate k using the following expression.
k = ln2/ t1/2 = ln2 / 14.3 d = 0.0485 d⁻¹
Step 3: Calculate the amount of P, given the initial amount (P₀) is 37.6 mg and the time elapsed (t) is 35.0 days
For first-order kinetics, we will use the following expression.
ln P = ln P₀ - k × t
ln P = ln 37.6 mg - 0.0485 d⁻¹ × 35.0 d
P = 6.88 mg
