Answer:
Mostly large grains, with a sticky texture, 55% sand, 40% clay, and 5% silt
Explanation: I took the test, hope it helps.
<span> First you need to know how many isotopes there are of silicon, and its average atomic units (look at periodic table). Then make up a system of equations to solve for it. Theres 3 stable silicon isotopes (28, 29, 30) so you will need to have 3 equations. You must be given the percent abundance of at least one of the isotopes to solve because here I can only see 2 equations (numbered down below) set x = percent abundance of si-28 y = percent abundance of si-29 z = percent abundance of si-30 since all of silicon atoms account for 100% of all silicon: x + y + z = 100% = 1 therefore: 1) x = 1 - y - z You also have 2) 28x + 29y + 30z = average atomic mass you can substitute x so that equation becomes: 28 (1 - y - z) + 29y + 30z = average atomic mass See how you have 2 variables here? You cant go on until you know the value of one isotope already or you have given a clue which you can derive the third equation</span>
It is letter C: Continental crust is thicker than oceanic crust.
Answer:<span>d. 145 minutes
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Half-life is the time needed for a radioactive to decay half of its weight. The formula to find the half-life would be:
Nt= N0 (1/2)^ t/h
Nt= the final mass
N0= the initial mass
t= time passed
h= half-life
If 25.0% of the compound decomposes that means the final mass would be 75% of initial mass. Then the half-live for the compound would be:
Nt= N0 (1/2)^ t/h
75%= 100% * (1/2)^ (60min/h)
3/4= 1/2^(60min/h)
log2 3/4 = log2 1/2^(60min/h)
0.41503749928 = -60min/h
h= -60 min / 0.41503749928= 144.6min
