4. If 175 undecayed nuclei remain from a sample of 2800 nuclei, how many half- lives have passed? (Show your work.) *
Your answer

X = 4

Explanation:

Start 2800

End 175

175 = 2800x(0.5)^X

175/2800 = 0.5^X

0.0625 = 0.5^X

log(0.5 x) = log(0.0625)

x · log(0.5) = log(0.0625)

-0.301x = -1.204

x = -1.204/-0.301

x = 4

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?