Answer:
Helium is the second element on the periodic table. It is located in period 1 and group 18 or 8A on the righthand side of the table. This group contains the noble gases, which are the most chemically inert elements on the periodic table. Each He atom has two protons and usually two neutrons and two electrons.
Explanation:
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Expansion
Explanation:
Expansion is the change is size of a body with increasing temperature and tension.
Bridges are built of iron. Iron thermally expands in the presence of increased temperature during the day. The length of the iron will increase by simple fractions. At night, when temperature drops, the bar returns back to its initial position.
- The allowance for expansion of the metal is made in order to prevent tension within the structure.
- Not doing this will cause the material to break since there is no free space for the bar to change shape.
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Expansion in gases brainly.com/question/9979757
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C. Digesting a sandwich
Is your answer
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Answer is: 0,0095 mol of hydrogen gas will be produced in reaction.
Chemical reaction: Ca + 2HCl → CaCl₂ + H₂.
m(Ca) = 0,38 g.
n(H₂) = ?
n(Ca) = m(Ca) ÷ M(Ca).
n(Ca) = 0,38 g ÷ 40 g/mol
n(Ca) = 0,0095 mol.
from reaction: n(Ca) : n(H₂) = 1 : 1.
n(H₂) = n(Ca) = 0,0095 mol.
n - amount of substance.
