Valance electrons are the extra electrons on the outermost orbital, that hasn't been filled yet. For example, Lithium would have one valence electron, on the 2s orbital, because that is an extra electron floating around that 2s orbital, that can be shared with others, since each element's goal is to have no valence electrons. If an orbital is filled, it therefore has no valence electrons, because valence electrons are only extra electrons, if that makes any sense.
There are many groups of the periodic table. These groups categorize electrons by the amount of valence electrons they have. The group on the far left, the alkali metals, all have one valence electrons. The alkali metals include Lithium, Sodium, and other elements, so therefore give away that one electron easily, because if they give it away they won't have any valence electrons. (This is why you often see salt, sodium chloride, because sodium gives away its one valence electron to chloride, who needs one electron to have no valence electrons.) One other notable group is the noble gases, on the far right of the periodic table. These elements have no valence electrons, so therefore won't bond easily with other elements.
Hope this helped!
Whats your question here?
The scenario that contains an exact number is 'A) You count 10 people in a room' (Option A).
<h3>What is the exact number?</h3>
An exact number can be considered a discrete variable because it does not involve a continuous range of values in a given measurement.
In conclusion, the scenario that contains an exact number is 'A) You count 10 people in a room' (Option A).
Learn more about discrete variables here:
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<u>Answer:</u> The half life of the sample of silver-112 is 3.303 hours.
<u>Explanation:</u>
All radioactive decay processes undergoes first order reaction.
To calculate the rate constant for first order reaction, we use the integrated rate law equation for first order, which is:
![k=\frac{2.303}{t}\log \frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%20%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken = 1.52 hrs
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= Initial concentration of reactant = 100 g
[A] = Concentration of reactant left after time 't' = [100 - 27.3] = 72.7 g
Putting values in above equation, we get:
To calculate the half life period of first order reaction, we use the equation:
where,
= half life period of first order reaction = ?
k = rate constant = 
Putting values in above equation, we get:
Hence, the half life of the sample of silver-112 is 3.303 hours.
Answer:
Examples of Solids
1. Brick
2. coin
3. Iron bar
4. rock
5. wood
Examples of Liquids
1. Blood
2. Honey
3. Wine
4. Water
5. oil
Examples of Gases
A gas does not have a defined shape or volume, so it can expand to fill any size or shape of a container. Particles in gases are widely separated, compared to those in liquids and solids.
Explanation:
