Answer:
D
more protons in the nucleus pull the electrons in, making the atomic radius smaller
Explanation: A p E X !! :)
The number of protons is same as periodic table number.
In this case 81 Periodic table number element has 81 Protons.
Answer:
MnO- Manganese Oxide
Explanation:
Empirical formula: This is the formula that shows the ratio of elements
present in a
compound.
How to determine Empirical formula
1. First arrange the symbols of the elements present in the compound
alphabetically to determine the real empirical formula. Although, there
are exceptions to this rule, E.g H2So4
2. Divide the percentage composition by the mass number.
3. Then divide through by the smallest number.
4. The resulting answer is the ratio attached to the elements present in
a compound.
Mn O
% composition 72.1 27.9
Divide by mass number 54.94 16
1.31 1.74
Divide by the smallest number 1.31 1.31
1 1.3
The resulting ratio is 1:1
Hence the Empirical formula is MnO, Manganese oxide
Answer:
D. CF₄
Explanation:
The compound with this molecular geometry is Carbon tetrafluoride (CF₄)
Carbon tetrafluoride (CF₄) also known as Tetrafluoromethane, is known to be the simplest perfluorocarbon. The compound, tetrafluoromethane is the hydrocarbon methane has been perfluorinated. It useful as a refrigerant but known to be a greenhouse gas. Due to the nature of the carbon-flourine bond, it has very high bonding strength. Its bonds are known to be the strongest single bonds in organic chemistry.
Option D is the correct answer.
8 valence electrons means that the element is stable. When we hear stable, we know the group to look at! Noble gases all have 8 valence electrons making them stable and have a full octet.
Here are some:-
Krypton
Argon
Neon