Answer:
0.50 mol
Explanation:
The half-life is <em>the time required for the amount of a radioactive isotope to decay to half that amount</em>.
Initially, there are 8.0 moles.
- After 1 half-life, there remain 1/2 × 8.0 mol = 4.0 mol.
- After 2 half-lives, there remain 1/2 × 4.0 mol = 2.0 mol.
- After 3 half-lives, there remain 1/2 × 2.0 mol = 1.0 mol.
- After 4 half-lives, there remain 1/2 × 1.0 mol = 0.50 mol.
Answer:
The length of a side of the square is 4.53 cm
Explanation:
Volume (V) = mass/density
mass = 3.4 mg = 3.4/1000 = 0.0034 g
density = 19.3 g/cm^3
V = 0.0034/19.3 = 1.76×10^-4 cm^3
Volume = area × thickness
Area = volume/thickness = 1.76×10^-4/8.6×10^-6 = 20.48 cm^2
Length of one side of the square = sqrt(area of square) = sqrt(20.48 cm^2) = 4.53 cm
Answer:
Saturated
Explanation:
If the sugar sits undissolved at the bottom even after vigorous stirring, the lemonade has dissolved all the sugar it can hold. The lemonade is saturated.
If the lemonade were <em>unsaturated</em>, it could hold more sugar and that at the bottom would continue to dissolve.
The lemonade cannot be <em>supersaturated </em>because, if it were, the solid at the bottom would serve as nuclei on which the excess sugar in the solution could form more crystals.
Redox is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a reduction process and a complementary oxidation process, two key concepts involved with electron transfer processes.
