Answer:
3. x 10⁸m/s
Explanation:
Given parameters:
Frequency of wave = 7.8 x 10⁶Hz
Unknown:
Speed of the wave = ?
Solution:
All electromagnetic radiation has a speed of 3. x 10⁸m/s in free space.
No matter the frequency and wavelength, they all have the same speed which is the same as the speed of light.
% m/v of the solution = 0.2%m/v
<h3>Further explanation</h3>

or
% m/v = g solute / 100 ml solution
Concentration : 2 g sodium borate / L water
For 10 L⇒20 g Sodium borate

Explanation:
The periodic table arranges elements based on their atomic numbers in a systematic fashion.
There are about 110 elements on the periodic table with each of them having their unique atomic numbers.
On periodic table, most atoms are designated as:
ₓⁿT
T is the symbol of the atom
X is the atomic number of the atom
n is the mass number
Atomic number is the number of protons in atoms in an element. Protons are the positively charged particles.
Mass number is the number of protons and neutrons in an atom. Both protons and neutrons are in the nucleus of an atom.
Atomic number = number of protons = number of electrons
Mass number = number of protons + number of neutrons
Number of neutrons = mass number - number of protons
Number of neutrons = mass number - atomic number
learn more:
Periodic table brainly.com/question/2014634
#learnwithBrainly
Data:
Q = 402.7 J → releases → Q = - 402.7 J
m = 16.25 g
T initial = 54 ºC
adopting: c = 4.184J/g/°C
ΔT (T final - T initial) = ?
Solving:
Q = m*c*ΔT
-402.7 = 16.25*4.184*ΔT
-402.7 = 67.99*ΔT


If: ΔT (T final - T initial) = ?


im guessing a natural resource? sorry thats the only answeri can think of