Answer:
The transition from lower energy level to higher energy level require a gain of energy.
Explanation:
When transition occur from lower energy level to higher energy level require a gain of energy. Electron could not jump unto higher energy level without gaining thew energy.
When electron jump into lower energy level from high energy level it loses the energy.
For example electron when jumped from 2nd to 3rd shell it gain energy and when in return back to 2nd shell from 3rd shell it loses energy.
The process is called excitation and de-excitation.
Excitation:
When the energy is provided to the atom the electrons by absorbing the energy jump to the higher energy levels. This process is called excitation. The amount of energy absorbed by the electron is exactly equal to the energy difference of orbits.
De-excitation:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations. this energy is exactly equal to the energy difference between the orbits. The characteristics bright colors are due to the these emitted radiations. These emitted radiations can be seen if they are fall in the visible region of spectrum.
Answer:
The molar mass of carbon
Explanation:
Before the mass (in grams) of two moles of carbon can be determined, <u>the molar mass of the element would be needed.</u>
<em>This is because the number of mole of an element is the ratio of its mass and the molar mass</em>. That is,
number of mole = mass/molar mass
Hence, the mass of elements can be obtained by making it the subject of the formular;
mass = number of mole x molar mass
<em>Therefore, the molar mass of carbon would be needed before the mass of 2 moles of the element can be determined.</em>
Answer:
A
Explanation:
The molecule with the strongest intramolecular bond is HF. Hydrogen fluoride is the answer due to the strong and highly electronegative nature of Fluorine.
- Fluorine is the most electronegative element in nature.
- When it combines with other substances, due to its electronegative property, it draws most of the electrons closest to itself in the bond.
- This tendency and ability makes the shared electrons closer the fluorine in the bond.
- The strong polarization that ensues confers a very strong covalent bond pair on the bond formed.
Mass of KNO₃ : = 40.643 g
<h3>Further explanation</h3>
Given
28.5 g of K₃PO₄
Required
Mass of KNO₃
Solution
Reaction(Balanced equation) :
2K₃PO₄ + 3 Ca(NO₃)₂ = Ca₃(PO₄)₂ + 6 KNO₃
mol K₃PO₄(MW=212,27 g/mol) :
= mass : MW
= 28.5 : 212,27 g/mol
= 0.134
Mol ratio of K₃PO₄ : KNO₃ = 2 : 6, so mol KNO₃ :
= 6/2 x mol K₃PO₄
= 6/2 x 0.134
= 0.402
Mass of KNO₃ :
= mol x MW KNO₃
= 0.402 x 101,1032 g/mol
= 40.643 g
Answer:
Metal
Explanation:
Lithium (Li), chemical element of Group 1 (Ia) in the periodic table, the alkali metal group, lightest of the solid elements. The metal itself—which is soft, white, and lustrous—and several of its alloys and compounds are produced on an industrial scale.
Atomic number: 3
Atomic weight: 6.941
