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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It is an example of physical change. The molecules are not changing, so it is not chemical, and a physical property is something that a physical thing has.
Answer:
Here's what I get.
Explanation:
Quinine contains phosphors, substances that glow when they are hit with certain wavelengths of light.
The phosphors in quinine absorb UV light, which is invisible to our eyes.
Electrons in the phosphors absorb the UV energy and are excited to higher energy levels.
When the electrons drop back to lower energy levels, they emit some of this energy as a glowing blue visible light.
Answer:
1.41 moles H2O2(with sig figs)
Explanation:
okay so what is the molar mass of H2O2= (1.008 g/mol)2+(16.00g/mol)2= (2.016+ 32.00) g/ mol
= 34. 02 g/mol
48.0g H2O2* 1 mol H2O2/ 34.02 g H2O2= 1.41 mol H2O2
Answer:
Corrosion
Explanation:
Silver, although known as a nobble metal, is also subject to corrosion process such as having silver tarnish when exposed to sulfur and air.
Tarnishing occurs on the surfaces of some metals such as brass, copper, and silver, which results in a corroded layer. Silver tarnish occurs from the chemical reaction that takes place when silver is exposed to sulfur which results in the formation of black Ag₂S
In order to restore the original silver surface, the silver tarnish (silver sulfide) layer is removed.
We have the statement presented here as follows;
The forks shown are made of silver (Ag). Some of the silver forks shown have lost their luster - they have become tarnished. This is an example of <u>Corrosion.</u>