Helium (He) has the lowest melting point of <span>-272.2 °C.</span>
This is due to the difference in density. The rock is
denser than the leaf. And also, the rock is denser than the liquid in the pond.
If the material is denser than the other material, it will sink. The same holds
true for the rock, it sinks. But when the material is less dense than the other
material, it floats. And it holds true for the leaf, it floats.
Answer:
1.99 x 10⁻¹⁸J
Explanation:
Given parameters:
Frequency of the wave = 3 x 10¹⁵Hz
Unknown:
Energy of the photon = ?
Solution:
To solve this problem, we use the expression below;
E = hf
Where E is the energy, h is the Planck's constant and f is the frequency
Now insert the parameters and solve for E;
E = 6.63 x 10⁻³⁴ x 3 x 10¹⁵ = 19.9 x 10⁻¹⁹J or 1.99 x 10⁻¹⁸J
Explanation:
Mg+O>MgO
Here the mg loses it electron and is oxidised and oxygen gains and is reduced.
Mg(2+)and O(2-)
Mg is a reducing agent it makes oxygen to be reduced while itself being oxidised and vice versa.