The melting point (or, rarely, liquefaction point) of a solid is the temperature at which it changes state from solid to liquid at atmospheric pressure. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard pressure.
Answer:
C.
Explanation: In nuclear fission and fusion reactions, some of the energy in matter is converted to energy. If you weigh the reactants and the products, the products will weigh less than the reactants. This is called the mass defect and is the result of turning matter into energy.
It has a role as a fertilizer. It is a potassium salt and an inorganic chloride.
Answer:
E = 9.95×10⁻¹⁹ J
Explanation:
Given data:
Wavelength = 2×10⁻⁷ m
Energy of photon = ?
Solution:
Formula:
E = hc/λ
h = 6.63×10⁻³⁴ Js
c = 3×10⁸ m/s
by putting values,
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 2×10⁻⁷ m
E = 19.89×10⁻²⁶Jm / 2×10⁻⁷ m
E = 9.95×10⁻¹⁹ J
Answer: the last choice, It separates dissolved substances, which is a physical change.
Explanation:
Physical changes do not modify the composition of the substances.
The substances that undergo a physical change do not brake or form chemical bonds, they just modify ther appearance: the size, the physical state (solid, liquid, or solid), the density, the shape, that kind of properties.
The salts dissolved and the water will have the same chemical properties in solution and after being separated, so they have not had a chemical change, they have only changed their appearance, so this explains why it is a physical change.