Answer:
Chemical indicator, any substance that gives a visible sign, usually by a color change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow color to an alkaline solution.
Answer:
electricity
Explanation:
i took the test and got the answer right.
Answer: longer wavelength and lower energy.
Explanation:
1) The wavelength is inversely related to the frequency. So, an electromagnetic wave with lower frequency will have longer wavelength.
This is the formula for electromagnetic waves:
λ = c / ν
where λ is the wavelength, c is the speed of light, and ν is the frequency.
2) Energy is directly related to the frequency.
This is the formula E = hν,
where E is the energy, h is Planck constant, and ν is the frequency.
So, the lower the frequency the lower the energy.
3) Conclusion:
<span>An electromagnetic wave that has a lower frequency than infrared radiation will have longer wavelength and lower energy than the infrared radiation</span>
<h3>
♫ - - - - - - - - - - - - - - - ~Hello There!~ - - - - - - - - - - - - - - - ♫</h3>
➷ It would depend on whether they would create an endothermic reaction or exothermic. For a hot pack, the chemicals would need to release energy (heat). However, a cold pack would need chemicals that need to draw heat from the surroundings to produce a cool sensation.
<h3><u>
✽</u></h3>
➶ Hope This Helps You!
➶ Good Luck (:
➶ Have A Great Day ^-^
↬ ʜᴀɴɴᴀʜ ♡
Answer:
932.44 km/s
Explanation:
Given that:
The work function of the magnesium = 2.3 eV
Energy in eV can be converted to energy in J as:
1 eV = 1.6022 × 10⁻¹⁹ J
So, work function = 
Using the equation for photoelectric effect as:
Also, 
Applying the equation as:
Where,
h is Plank's constant having value 
c is the speed of light having value 
m is the mass of electron having value 
is the wavelength of the light being bombarded
v is the velocity of electron
Given, 
Thus, applying values as:
v = 9.3244 × 10⁵ m/s
Also, 1 m = 0.001 km
<u>So, v = 932.44 km/s</u>
