Answer:
When the excited electron fall back to the lower energy levels the energy is released in the form of radiations.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
Explanation:
The electron is jumped into higher level and back into lower level by absorbing and releasing the 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. For example if electron jumped from K to L it must absorbed the energy which is equal the energy difference of these two level. The excited electron thus move back to lower energy level which is K by releasing the energy because electron can not stay longer in higher energy level and comes to ground state.
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:
a) No. of moles of hydrogen needed = 5.4 mol
b) Grams of ammonia produced = 27.2 g
Explanation:
a)
No. of moles of nitrogen = 1.80 mol
1 mole of nitrogen reacts with 3 moles of hydrogen
1.80 moles of nitrogen will react with
= 1.80 × 3 = 5.4 moles of hydrogen
b)
No. of moles of hydrogen = 2.4 mol
It is given that nitrogen is present in sufficient amount.
3 moles of hydrogen produce 2 moles of 
2.4 moles of hydrogen will produce
= 
Molar mass of ammonia = 17 g/mol
Mass in gram = No. of moles × Molar mass
Mass of ammonia in g = 1.6 × 17
= 27.2 g
Answer:
2.03 atm
Explanation:
Number of moles of He = 1g/4g/mol = 0.25 moles
Number of moles of F2 = 14.0g/38 g/mol = 0.37 moles
Number of moles of Ar=19.0g/40g/mol = 0.48 moles
Total number of moles = 0.25 + 0.37 + 0.48 = 1.1 moles
From;
PV=nRT
P= pressure of the gas mixture
V= volume of the gas mixture
n= total number of moles of the gas mixture
R= gas constant
T= temperature of the gas mixture
P= nRT/V
P= 1.1 × 0.082 × 293/13
P= 2.03 atm
Answer:
Cation
Anion
Cation
Cation
Explanation:
If an atom, or atoms, has a balanced number of electrons (negative charge) and protons (positive charge) they are neutral overall. However, if they are not balanced, they will be charged. These charged species are called ions.
What is an anion?
An anion has more electrons than protons, consequently giving it a net negative charge. For an anion to form, one or more electrons must be gained, typically pulled away from other atoms with a weaker affinity for them. The number of electrons gained, and so the charge of the ion, is indicated after the chemical symbol, e.g. chlorine (Cl) gains one electron to become Cl-, whilst oxygen (O) gains two electrons to become O2-.
What is a cation?
A cation has more protons than electrons, consequently giving it a net positive charge. For a cation to form, one or more electrons must be lost, typically pulled away by atoms with a stronger affinity for them. The number of electrons lost, and so the charge of the ion, is indicated after the chemical symbol, e.g. silver (Ag) loses one electron to become Ag+, whilst zinc (Zn) loses two electrons to become Zn2+.
Source: Cation vs Anion: Definition, Chart and the Periodic Table By
Karen Steward (PhD)
