Answer:
A
Explanation:
The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Consider the table below, which shows data from the first six elements of the periodic table. Consider the element helium. Its atomic number is 2, so it has two protons in its nucleus.
The 3% mass/volume H₂O₂ means 3 g of H₂O₂ in 100 ml of water.
Now, Molarity (M) = No. of moles of H₂O₂ / Volume of solution in liter
No. of moles of H₂O₂ = Mass / Molar mass = 3 g / 34 g/mol = 0.088 mol
So, molarity = 0.088 × 1000 ml / 100 ml = 0.88 M
In case of 2.25 % H₂O₂,
No of moles = 2.25 g / 34 g/mol = 0.066 mol
Molarity = 0.066 mol / 0.100 L = 0.66 M.
bromine
Explanation:
halogens are a group of elemnts simlar to eachother
flourine, chlorine, and bromine
<span>An object at rest will stay at rest unless acted upon by a unbalanced force.
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