Noble gases show degrees of reactivity. These elements have generally complete electron shells. Noble Gases Include: Helium, Neon, Argon, Krypton, Xenon, Radon, Ununoctium. Reactive elements that form compounds known as halides.
Radioactive decay => C = Co { e ^ (- kt) |
Data:
Co = 2.00 mg
C = 0.25 mg
t = 4 hr 39 min
Time conversion: 4 hr 39 min = 4.65 hr
1) Replace the data in the equation to find k
C = Co { e ^ (-kt) } => C / Co = e ^ (-kt) => -kt = ln { C / Co} => kt = ln {Co / C}
=> k = ln {Co / C} / t = ln {2.00mg / 0.25mg} / 4.65 hr = 0.44719
2) Use C / Co = 1/2 to find the hallf-life
C / Co = e ^ (-kt) => -kt = ln (C / Co)
=> -kt = ln (1/2) => kt = ln(2) => t = ln (2) / k
t = ln(2) / 0.44719 = 1.55 hr.
Answer: 1.55 hr
The mass (in grams) of the silicon present in the computer chip is 2.19 g
From Avogadro's hypothesis,
6.02×10²³ atoms = 1 mole of Si
But
1 mole of Si = 28 g
Thus, we can say that:
6.02×10²³ atoms = 28 g of Si
- With the above information, we can obtain the mass of silicon, Si present in the computer chip. This can be obtained:
6.02×10²³ atoms = 28 g of Si
Therefore,
4.71×10²² atoms = (4.71×10²² × 28) / 6.02×10²³ g of Si
4.71×10²² atoms = 2.19 g of Si
Thus, the mass of silicon, Si present in the computer chip is 2.19 g
Learn more on Avogadro's number: brainly.com/question/25811549