Explanation:
1. Explain how groups 1A-8A in the periodic table are organized by their number of valence electrons.
The valence electrons in an atom are the outermost shell electrons. They are the most loosely held electrons in an atom.
Coincidentally, the periodic table of elements divided into vertical groups and horizontal periods can be said to be arranged according to the number of valence electrons.
- Atomic numbers are used to arrange elements on the periodic table.
- Down a group, the number of electronic shell increases. More electrons are added to new energy levels.
- As we move from left to right across a period, the number of electrons in elements increases but electronic shell is the same.
- Down a group electronic shell increases but the number of valence electrons are the same.
- All elements in Group 1A has just one valence electrons, Group 2A has two valence electrons.........Group 8A has eight valence electrons.
- Moving across groups is synonymous to moving from left to right on the periodic table.
- Due to this trend, the periodic table is arranged based on the number of valence electrons.
3. explain how you know the number of valence electrons for each group.
The number of valence electrons in a group is the group number:
Group Number valence electrons
1A 1
2A 2
3A 3
4A 4
5A 5
6A 6
7A 7
8A 8
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Answer:
CO2 (g)
Explanation:
In solids the interatomic or intermolecular space is least . It is most pronounced in gases . That is why inter molecular or interatomic attraction is least in gases . That is why gas flows .
Hence , when we try to compress a gas , due to inter molecular space , it is most likely to get compressed . It will be least compressed when we try to compress a solid because of lack of intermolecular space .
Answer:
Correct option is
B
5 liters of CH
4
(g)NO
2
at STP
No. of molecules=
22.4
5
mol=
22.4
5
×N
A
molecules
A) 5ℊ of H
2
(g)
No. of moles=
2
5
mol=
2
5
×N
A
molecules
B) 5l of CH
4
(g)
No. of moles of CH
4
=
22.4
5
mol=
22.4
5
N
A
molecules
C) 5 mol of O
2
=5N
A
O
2
molecules
D) 5×10
23
molecules of CO
2
(g)
Molecules of 5l NO
2
(g) at STP=5l of CH
4
(g) molecules at STP
Therefore, option B is correct.
Answer:
The volume in cubic centimeters is 250
Explanation:
The rule of three or is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other), the direct rule of three must be applied. To solve a direct rule of three, the following formula must be followed:
a ⇒ b
c ⇒ x
So:
The direct rule of three is the rule applied in this case where there is a change of units. To perform this conversion of units, you must first know that 1 mL = 1 cubic centimeters. So, if 1 cubic centimeters is 1 mL, how many cubic centimeters equals 250 mL?
cubic centimeters= 250
<u><em>The volume in cubic centimeters is 250</em></u>
