Physical changes are those which do not affect the chemical properties of a substance. For example, when a paper is cut, the two pieces obtained are still paper. The chemical properties have not changed. Only, physically when one piece is cut to two. A chemical change occurs when the chemical properties change and a new substance with different chemical properties is obtained. For example, when the paper is burnt, it turns to ashes. Hence, this is a chemical change.
When a substance undergoes a physical change, the physical properties of the substance changes like the state (solid to liquid during melting), shape, size, volume etc. Many physical changes are reversible whereas, in general many chemical changes are irreversible.
Coulomb's law applies to all charges. It doesn't care what the specific
purpose of the individual charge may be at the moment.
Wavelength should be in meters which is 0.023 m
c = 3.7 * 0.023 = 0.0851 (3 sf)
Answer:
CuCl₂ + H₂S → CuS + 2HCl
Explanation:
The unbalanced reaction expression is given as;
CuCl₂ + H₂S → CuS + HCl
The problem here involves balancing of chemical equations.
We use a mathematical approach to solve this problem. Here assign coefficients a, b, c and d as values that will effect the balance;
aCuCl₂ + bH₂S → cCuS + dHCl
Conserving Cu: a = c
Cl: 2a = d
H: 2b = d
S: b = c
let a = 1; c = 1, b = 1 and d = 2
CuCl₂ + H₂S → CuS + 2HCl
Answer:
2. F g decreases to 1/9
Explanation:
The formula for calculating the Force of gravity between two masses separated by a distance is expressed as;
F = GMm/d² ... 1
If the distance is tripled, the new force will be;
F1 = GMm/(3d)²
F1 = GMm/9d² ... 2
Divide equation 1 by 2
F/F1 = GMm/d²÷GMm/9d²
F/F1 = GMm/d²×9d²/GMm
F/F1 = 1 * 9
F = 9F1
F1 = 1/9 F
<em>This means that the new force decreases to 1/9</em>