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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Answer:
8L
Explanation:
Using Boyle's law which states that the volume of a given mass of gas is inversely proportional to the pressure, provided temperature remains constant
P1V1= P2V2
P1 = 2atm, V1 = 12L ,
P2 = 3atm , V2 =
12 × 2 = V2 × 3
Divide both sides by 3
V2 = 24 ÷ 3
V2 = 8L
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3 mass number- proton number
Dmitri Mendeleev, he realized that the physical and chemical properties of elements were related to their atomic mass and arranged them into groups (columns)