<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>
Answer:
-1, -4
Explanation:
Factoring, you get:
To find what x can be, you need to realize what could make this equation true. To set the left side equal to 0, either one of the terms in parentheses must be equal to 0. To do that, x must be the negative of the other term, so that they can cancel each other out. Therefore, x is -4 and -1. Hope this helps!
Answer:
B6Br4
Explanation:
Chemical formula gives a representation of the number of atoms that each element in a compound or molecule. In this question which is asking to give the formula of hexaboron tetrabromide, the hexa means 6 while the tetra means four.
Since the number of atoms of each element is written as a prefix before the main element, this means that the chemical formula of hexaboron tetrabromide will be B6Br4.
Answer:
CH2- CH3
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CH3 - CH2 - C - CH - CH2 - CH2 - CH3
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CH3 CH3
Explanation:
Heptane
CH3 - CH2 - CH2 - CH2 - CH2 - CH2 - CH3
3 ethyl 3, 4 dimethylheptane
CH2- CH3
|
CH3 - CH2 - C - CH - CH2 - CH2 - CH3
| |
CH3 CH3