Candela is the correct answer. In measuring the brightness or luminosity of the bulb and you want to use the metric system, candela is the unit to be used. You are correct that candela is the unit of light intensity. The term candela is the Latin for candle which signifies light.<span> </span>
<span>Not all solids melt when they are heated. Some may undergo chemical changes as a result of heating. For example paper burns rather than melts</span>
Conc = moles / Vol you have C but need to find moles
moles KCl = mass / molar mass
25 g / 74.55 g,p;
0.335 moles
So rearrange the formula to find volume. Vol = moles / Conc
0.335 moles / 0.750 mol / L = 0.447 L or 447 mL
The answer in this question is 447 mL.
The correct answer is Strontium-90.
Strontium-90 breaks down into yttrium-90.
Strontium-90 is a radioactive isotope of strontium. It undergoes β− decay into yttrium-90. A decay energy of 0.546 MeV is also released.
⁹⁰₃₈Sr -> ⁰₋₁e + ⁹⁰₃₉Yr
Beta particle has the charge and mass of an electron. Upon the release of a beta particle, the mass number of Sr remains unchanged but the atomic number of Sr increases by 1. As a result both Sr and Yt have mass number 90, however, Sr and Yt have atomic numbers 38 and 39 respectively.