Answer:
The ionization energy of each successive element generally decreases
Explanation:
The ionization energy increases in the periods of the periodic table and decreases in the groups. If the atom is very small, we will need a lot of energy to release the electron, while if the atom is larger the energy will be greater.
Answer:
2.67g of NH4Cl are required
Explanation:
Molarity is an unit of concentration in chemistry defined as the moles of solute (In this case, NH4Cl), per liter of solution.
To prepare 100mL of a 0.50M are required:
100mL = 0.100L * (0.50 moles / L) = 0.0500 moles NH4Cl
As molar mass of NH4Cl is 53.491g/mol:
0.0500 moles * (53.491g / mol) =
<h3>2.67g of NH4Cl are required</h3>
Answer:
a solution of acetic acid and sodium acetate
Explanation:
A buffer solution is defined as a solution which resist a change in pH when small quantity of a strong acid or a strong base are added. A buffer solution is made up of mixture of a weak acid and its conjugate base or a mixture of a weak base and its conjugate acid.
Acetic acid is the only option because it is a weak acid with a corresponding conjugate base, acetate. Unlike a solution of sulfuric acid and sodium sulfate in which the sulfuric acid is a strong acid which doesn’t qualify it to be a buffer solution. The remaining options have different acid compounds paired together which makes them invalid too.
These are three questions and three complete answers
Answer:
a) Cr²⁺: [Ar] 4s² 3d²
b) Cu²⁺: [Ar] 4s² 3d⁷
c) Co³⁺: [Ar] 4s² 3d⁴
Explanation:
<u>a) Cr²⁺</u>
- Number of elecrons of the neutral atom: 24
- Number of electrons of the ion: 24 - charge = 24 - 2 = 22.
Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....
Hence, for 22 electrons you get:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d²
- Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:
[Ar] 4s² 3d²
<u>b) Cu²⁺</u>
- Number of elecrons of the neutral atom: 29
- Number of electrons of the ion: 29 - charge = 29 - 2 = 27.
Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....
Hence, for 27 electrons you get:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷
- Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:
[Ar] 4s² 3d⁷
<u>c) Co³⁺</u>
- Number of elecrons of the neutral atom: 27
- Number of electrons of the ion: 27 - charge = 27 - 3 = 24.
Fill the orbitals in increasing order of energy. Using Aufbau's rules the order is: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ .....
Hence, for 24 electrons you get:
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁴
- Abbreviated notation: since the last complete level is the number 3s² 3p⁶, you use the noble gas of the period 3, which is Ar, and the configuration is:
[Ar] 4s² 3d⁴
Answer:
Explanation:
By observing chemical reactions, we are able to understand and explain how the natural world works. Chemical reactions turn food into fuel for your body, make fireworks explode, cause food to change when it is cooked, make soap remove grime, and much more.
