Explanation:
An atom undergoes alpha decay by losing a helium atom.
So when bismuth undergoes alpha decay, we have;
²¹⁰₈₃Bi --> ⁴₂He + X
Mass number;
210 = 4 + x
x = 206
Atomic number;
83 = 2 + x
x = 81
The element is Thallium. The symbol is Ti.
For the second part;
X --> ⁴₂He + ²³⁴₉₀Th
Mass number;
x = 4 + 234 = 238
Atomic Number;
x = 2 + 90 = 92
The balanced nuclear equation is;
²³⁸₉₂U --> ⁴₂He + ²³⁴₉₀Th
Answer:
The cell theory claims these three components:
1. cell is the smallest functional unit of life: It can be observed under the microscope that cells have various type of molecules and organelles present and have adifferent functional role in the cell which explains that the cell is the smallest unit of life as its molecules or organelles can not carry the life process on their own.
2. All organisms are made up of cells: From bacteria and archaea to human and other life forms are made up of a single cell or organization of cells in a specific pattern it also can be observed by the microscopic of blood or other tissue or cell of an organism.
3. Arise from pre-existing cell: The cells are can be studied under a microscope during cell division where we can observe that new cells come from the pre existing cell by the cell division.
Answer: There are 
molecules 
gas are in 756.2 L.
Explanation:
It is known that 1 mole of any gas equals 22.4 L at STP. Hence, number of moles present in 756.2 L are calculated as follows.
According to mole concept, 1 mole of every substance contains 
molecules.
Therefore, molecules of S present in 33.76 moles are calculated as follows.
Thus, we can conclude that there are molecules gas are in 756.2 L.
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