Explanation:
the stationary phase in TLC is a <u>silica gel coated metal plate or paper</u>.
The<u> individual</u> component of the mixure will travel a greater distance up the plate, resulting in a <u>Rf</u> value for the component.
the <u>p-Xylene spot </u> will travel a greater distance as it is the <u>lighter</u> component
Bromobenzene will travel least as it is the <u>heavier</u> component.
thin layer chromatography (TLC) is a type of chromatographic seperation technique that is based on the molecular size of components. the Rf value is the distance covered by the component relative to that travelled by the solvent which is the mobile phase
The change in energy level was experienced by the electron that moved from a higher to a lower level. This does not affect the nucleus, so the nucleus itself does not change energy levels. It takes more energy to hold an electron at a higher than a lower energy level, so the change in energy levels means that some energy was released by the electron, and this is choice (2).
When you’re substance either starts to smell, smoke, explode, change color. Any of those happening are proof of a chemical reaction.
Answer:
4- radioactive isotopes
Explanation:
I don't remember exactly but this question was on the regents
Answer:
Yup! The answer is 50 J/g* °C
Explanation:
I also took the test but I know how to work out the problem for anyone who wants to know how to solve it.
Remember the formula q = m*C*ΔT
m = the mass in grams
C = the specific heat Capacity
ΔT = change in time
q = amount of energy
So, find out what was given and what we need to look for:
m = 40 g
C = ?
ΔT = we're heating up (the temperature increases) a chemical so it needs to be a positive number. 25 - 10 = 15 °C
q = 30000 Joules
Now, set up the equation:
q = m*C*ΔT
30000 = 40 * C * 15
Multiply 40 and 15 to get 600:
30000 = 600 * C
Divide both sides by 600 to get C by itself (plug this into your calculator):
30000/600 = 600 * C/600
You are left with 50 = C
Now, you just need to plug in the units to get B. 50 J/g* °C
I hope I helped clear up any confusion! :D
