Radio - Radio station transmits radio wavelength which is received by the
Radio.
<span>
Microwaves - Microwave Oven to heat up foods. </span>
<span>IR (infrared) - TV remote Control, to transmit IR light to a sensor in the TV so it can do some functions like increasing the volume, changing the channel etc. </span>
<span>Visible light - Sunlight or Light Bulbs </span>
<span>Ultraviolet - UV Lamps for sun tan, for detecting forged money </span>
<span>X-rays - Chest X-ray machines, Backscatter Xray (body scanner in airport security)
</span>
Gamma rays - Gamma rays<span> Medical Equipment which are used to kill cancer cells, to sterilize medical </span>equipment<span> </span>
Given two electrons with charge of 1.5x10^-10 m
The electostatic force between them is determined by this formula:
F = kq1q2/r^2
where
k = 9x10^9
q1 = q2 = 1.5x10^-10
r = 2.82x10^-15
F = 9x10^9 * (1.5x10^-10)^2 / 2.82x10^-15
= 71808.51
A negative formation enthalpy means that the reaction is exothermic, or that heat is released during the process.
(C,)
When the concentration is expressed in molality, it is expressed in moles of solute per kilogram of solvent. Since we are given the mass of the solvent, which is water, we can compute for the moles of solute NaNO3.
0.5 m = x mol NaNO3/0.5 kg water
x = 0.25 mol NaNO3
Since the molar mass of NaNO3 is 85 g/mol, the mass is
0.25 mol * 85 g/mol = 21.25 grams NaNO3 needed
