Answer:
A. Warning
Explanation:
Out of all said choices, the best choice would be warning since it would fit the sentence the most.
"A Warning notifies you that danger is present." compared to:
"A Hazard notifies you that danger is present."
"A Safety notifies you that danger is present."
"A Danger notifies you that danger is present."
It's a physical change because the composition of the salt hasn't change. Only the change in substance/form has occured. To tell if something has undergone physical change is:
• Melting
• Boiling
• Freezing
• Condensing
• Breaking
• Bending
• Dissolving
• Molecules can change motion and proximity
To tell if something changed chemically:
• Molecules rearrange with other molecules to make new substance
• Can be production of flames
• Color change
• Bubbling/fizzing
• Temp. change
• change in composition
Salt=compound, soda=liquid solution, aluminum foil=element, milk=colloid,
steel=solid solution
Answer:
Option C, (Actual yield ÷ percent yield) × 100
Explanation:
Theoretical yield is defined as the total amount of product formed for given reactants in a chemical reaction. It is an ideal case which assumes no exceptions or wastage.
The mathematical relation between the actual yield, percent yield and theoretical yield is as follows -
Where
P.Y. represents the percent yield a
M A.Y. represents the mass obtained from actual yield
M T.Y. represents the mass obtained from theoretical yield
Hence, if we rearrange the formula, we get -
Hence, option C is correct
A frequency of 60 MHz is close to the lower end of the old VHF-TV band.
c = f λ ...... where c is the speed of light, f is the frequency and λ is the wavelength
λ = c / f = 3.00x10^8 m/s / 6.0x10^7 1/s
λ = 5.0 m
