<u>Answer:</u> The isotopic symbol of barium is 
and that of strontium is 
<u>Explanation:</u>
Nuclear fission reactions are defined as the reactions in which a heavier nuclei breaks down in two or more smaller nuclei.
In a nuclear reaction, the total mass and total atomic number remains the same.
- For the given fission reaction:
Total mass on reactant side = total mass on product side
235 + 1 = A + 94 + 3
A = 139
Total atomic number on reactant side = total atomic number on product side
92 + 0 = Z + 36 + 0
Z = 56
The isotopic symbol of barium is 
- For the given fission reaction:
Total mass on reactant side = total mass on product side
235 + 1 = A + 143 + 3
A = 90
Total atomic number on reactant side = total atomic number on product side
92 + 0 = Z + 54 + 0
Z = 38
The isotopic symbol of strontium is
Hence, the isotopic symbol of barium is and that of strontium is
The compound 
is formed only by sharing of electrons between the atoms. The structure of the compound is shown in the image.
Each line between two atoms represents the sharing of an electron pair which results in the formation of a single bond. Since, carbon has 4 electrons in its valence shell and hydrogen has 1 electron in its valence shell so in order to complete the octet ( to have 8 electrons in their valence shell, noble gas configuration) to attain stability carbon needs 4 more electrons and hydrogen needs 1 electron. So, sharing of electron will occur as shown in the image and the formed compound is stable in nature.
Since, the bond that is formed by sharing of electrons between atoms is known as covalent bond. So, covalent bonding is most important in .
Answer:
The central atom has 3 electron domains.
Explanation:
According to the Valence Shell electron pair repulsion theory (VSEPR) put forward by Gillespie and Nyholm in 1957, the shape of a molecule is determined by repulsion between all the electron pairs (electron domains) present in the valence shell.
The electron pairs or electron domains are known to position themselves as far apart in space as possible in order to minimize repulsions.
Hence, when the central atom of a molecule contains three electron domains, they are positioned at an angle of 120° from each other to minimize repulsions. Hence the answer.
Answer:
A)21
Explanation:
To know the difference between the number of electrons in the two atoms, we must first know the number of electrons in the atoms.
For Selenium, Se, we have 34 electrons. The element is in group 6 on the periodic table.
Aluminum on the other hand is in the Boron family with a total of 13 electrons.
The difference,( 34-13) electrons gives a total of 21 electrons
<h2>Answer : Option B) Ozone</h2><h3>Explanation :</h3>
The layer of atmosphere which contains a substance(Ozone) that was created from a product of living thins (oxygen) and protects living things (from harmful UV rays).
Oxygen in the atmosphere reacts in presence of UV rays and forms Ozone.
This ozone forms a protective layer around the earth and protects it from harmful UV rays.
