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
BeCl2 = Beryllium Chloride
2H2O = 2 molecules of H2O (water)
LiNO2 = Lithium Nitrate
H2O = water
Answer:
ΔE = 5.02 x 10⁻¹⁹ j
Explanation:
ΔE (photon) = h·f = (6.63 x 10⁻³⁴ j·s)(7.57 x 10¹⁴ s⁻¹) = 5.02 x 10⁻¹⁹ j
h = Planck's Constant = 6.63 x 10⁻³⁴ j·s
f = frequency (given) = 7.57 x 10¹⁴ s⁻¹
Answer:
A forensic light source is a crime scene investigator's and lab technician's tool for enhancing observation, photography and collection of evidence including latent fingerprints, body fluids, hair and fibers, bruises, bite marks, wound patterns, shoe and foot imprints, gun shot residues, drug traces, questioned
<span>2 Al+6 HBr = 2 AlBr</span>₃ <span>+ 3 H</span>₂
2 moles Al --------- 6 moles HBr ----------- 3 moles H₂
3.22 moles Al ------ 4.96 moles HBr ----- ( moles H₂ )
moles H₂ = 4.96 x 3 / 6
moles H₂ = 14.88 / 6
= 2.48 moles of H₂
hope this helps!
