C. Not each element has a known neutron number
Answer:
1. Mg (s) + 2Na+(aq) → 2Na(s) + Mg²⁺(aq)
2. 2K(s) + Cd²⁺(aq) → 2K⁺(aq) + Cd(s)
Explanation:
The net ionic equation of a reaction express only the chemical species that are involved in the reaction:
1. Mg (s) + Na2CrO4 (aq) → 2Na + MgCrO4(aq)
The ionic equation:
Mg (s) + 2Na+(aq) + CrO4²⁻ (aq) → 2Na + Mg²⁺ + CrO4²⁻(aq)
Subtracting the ions that don't change:
<h3>Mg (s) + 2Na+(aq) → 2Na + Mg²⁺</h3>
2. 2K(s) + Cd(NO3)2(aq) → 2KNO3(aq) + Cd(s)
The ionic equation:
2K(s) + Cd²⁺(aq) + 2NO3⁻(aq) → 2K⁺(aq) + 2NO3⁻(aq) + Cd(s)
Subtracting the ions that don't change:
<h3>2K(s) + Cd²⁺(aq) → 2K⁺(aq) + Cd(s)</h3>
Answer:
1. Orbital diagram
2p⁴ ║ ↑↓ ║ "↑" ║ ↑
2s² ║ ↑↓ ║
1s² ║ ↑↓ ║
2. Quantum numbers
- <em>n </em>= 2,
- <em>l</em> = 1,
- = 0,
- = +1/2
Explanation:
The fill in rule is:
- Follow shell number: from the inner most shell to the outer most shell, our case from shell 1 to 2
- Follow the The Aufbau principle, 1s<2s<2p<3s<3p<4s<3d<4p<5s<4d<5p<6s<4f<5d<6p<7s<5f<6d<7p
- Hunds' rule: Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin).
So, the orbital diagram of given element is as below and the sixth electron is marked between " "
2p⁴ ║ ↑↓ ║ "↑" ║ ↑
2s² ║ ↑↓ ║
1s² ║ ↑↓ ║
The quantum number of an electron consists of four number:
- <em>n </em>(shell number, - 1, 2, 3...)
- <em>l</em> (subshell number or orbital number, 0 - orbital <em>s</em>, 1 - orbital <em>p</em>, 2 - orbital <em>d...</em>)
- (orbital energy, or "which box the electron is in"). For example, orbital <em>p </em>(<em>l</em> = 1) has 3 "boxes", it was number from -1, 0, 1. Orbital <em>d</em> (<em>l </em>= 2) has 5 "boxes", numbered -2, -1, 0, 1, 2
- (spin of electron), either -1/2 or +1/2
In our case, the electron marked with " " has quantum number
- <em>n </em>= 2, shell number 2,
- <em>l</em> = 1, subshell or orbital <em>p,</em>
- = 0, 2nd "box" in the range -1, 0, 1
- = +1/2, single electron always has +1/2
Answer:
I think B but I'm not sure.
Explanation:
Divide the mass of chlorine by the molar mass of cobalt chloride, then multiply by 100.
Molar Mass of Cobalt Chloride.
Mass of Chlorine in Cobalt Chloride.
Percent Composition of Chlorine.