What you need to do is find 1/8 of 50
you can just divide 50 by 8 to get 6.25
so now you have to find how many days it will take till there are 6.25 grams of iodine left
every 8.1 days its mass is split in half
so start splitting it in half and every time you do, you add 8.1 days
50/2 =25 8.1
25/2 =12.5 + 8.1
12.5/2= 6.25 +8.1
now you have reached 1/8 of the original amount of Iodine-131
so to find how long it took just add 8.1+8.1+8.1
(this is the same as 8.1x3)
which equals 24.3
it will take 24.3 days for Iodine 131 to decay to 1/8 of its original mass.
(good luck on the regent if thats what your studying for :)
Answer:
Our Solar System may be home, but researchers are now discovering that it's not really much like the other kids. According to a survey of 909 planets orbiting 355 stars, our home planetary system is a little on the dishevelled side - and others are a lot more orderly.
Explanation:
Answer:
A vacuum flask is usually used to insulate it's contents… I've used them for a multitude of things ranging from keeping my coffee warm, to keeping liquid nitrogen from evaporating.
The reason these types of flasks are so efficient has to do with their thermodynamic properties. To understand how a vacuum flask works, we need to know the basic properties of a vacuum. Air just like any other molecule is a conductor of heat.
Firstly, a “layer of vacuum” is created around the thermos, it's crucial that the chamber is depressurized*.
Answer:
my define it will be turst me is c
Answer:
155 kJ
Explanation:
The energy change will be the energy of the reactants less the energy of the products. And the energy of each compound is the sum of the energy of their bonds. Let's call y the N-Br strength.
3HOBR = 3x(459 + 201) = 1980 kJ
NH₃ = 3x386 = 1158 kJ
3H₂O = 3x(2x459) = 2754 kJ
NBr₃ = 3y
3y + 2754 - 1158 - 1980 = 81
3y -384 = 81
3y = 465
y = 155 kJ