Answer: The nuclide symbol of X is 
Explanation:
The given nuclear reaction is a type of alpha decay process. In this process, the nucleus decays by releasing an alpha particle. The mass number of the nucleus is reduced by 4 units and atomic number is also decreased by 2 units. The particle released is a helium nucleus.
The general equation representing alpha decay process is:

For the given equation :

As the atomic number and mass number must be equal on both sides of the nuclear equation:

Thus the nuclide symbol of X is 
Answer:
Arrow.
Explanation:
Hello!
In this case, since chemical reactions are characterized by the presence of some species at the left on an arrow representing the reactants and at the right the products, we understand that the arrow, separating reactants and products is understood as "produces" or in very chemical words "yields"; therefore, the symbol that takes the place of the word yields is an arrow.
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<u>Importance </u><u>of </u><u>Circulatory </u><u>System</u>
- This system helps in transportation of respiratory gases like O2 and CO2, nutrients, hormones, enzymes, minerals, waste products.
- It helps in storage of essential substances for future use.
- It also generates heat to the body.
Hope you could understand.
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