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
Answer:
Matter is something that takes up space and has volume?
Hope it helps! Tell me if wrong too. :)
Explanation:
Mole =mass ÷ Mr
∴mass = mole×Mr =0.10 × (23+35.5) = 5.85
the answer is D...
The Mr is obtained from the periodic table
Magnesium is in Group 2 (sometimes called Group II or 2A). Since it is in Group 2 it will have 2 valence electrons. When you draw the Lewis structure for Magnesium you'll put two "dots" or valance electrons around the element symbol (Mg).
An element is a form of matter that is made of only one type of atom