<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>
<span>Wave A will have a higher pitch than wave B.. This is not true becasue b has the higher PITCH becasue it's closer together.
Wave B will have a lower pitch than wave A... This basically A but worded differently.
Wave A will have a louder sound than wave B... This is CORRECT becasue it's louder the waver are bigger, so it's louder. But it has a lower pitch, 2 different things.
Wave B will have a louder sound than wave A. False..</span><span />
Answer: D
Explanation: Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te) and, Astatine (At) are all metalloids
Answer:
0.48 moles
Explanation:
The bromide has a molarity of 2.6M.
This simply means that in 1dm^3 or 1000cm^3 of the solution, there are 2.6 moles.
Now, we need to get the number of moles in 185ml of the bromide. It is important to note that the measurement ml is the same as cm^3.
We calculate the number of moles as follows.
If 2.6mol is present in 1000ml
x mol will be present in 185 ml.
To calculate x = (185 * 2.6) ÷ 1000
= 0.481 moles = 0.48 moles to 2 s.f
