Staals half
1 gram left
0.3 grams left
half lives are normally written in years
it goes likt this

A=final amount
P=initila amount
t=time elapsed
h=time half life is (same units as time)
let's use days as the units of time
we are given
initial amount=1gram
final amount=0.3gram
time=4 days
so

solve for h

take the ln of both sides


times both sides by h

divide both sides by ln(0.3)

use calculator
h=2.30287
3 sig figs
h=2.303 days
Answer:
61
Step-by-step explanation:
and let c looks to be a right angle
Wouldn’t that just be infinitely?
Answer: A) is the right answer. 
Step-by-step explanation:
Given product : 
To multiply above expression, first we need to combine like terms and then we need to use the law of exponents.
![2.3\times3\times10^{-3}\times10^8\\=(2.3\times3)\times(10^{-3}\times10^8)\\=6.9\times10^{-3+8}......[\text{by law of exponents }a^n\cdot\ a^m=a^{m+n}]\\=6.9\times10^{5}](https://tex.z-dn.net/?f=2.3%5Ctimes3%5Ctimes10%5E%7B-3%7D%5Ctimes10%5E8%5C%5C%3D%282.3%5Ctimes3%29%5Ctimes%2810%5E%7B-3%7D%5Ctimes10%5E8%29%5C%5C%3D6.9%5Ctimes10%5E%7B-3%2B8%7D......%5B%5Ctext%7Bby%20law%20of%20exponents%20%7Da%5En%5Ccdot%5C%20a%5Em%3Da%5E%7Bm%2Bn%7D%5D%5C%5C%3D6.9%5Ctimes10%5E%7B5%7D)
Thus, the answer is
.