Answer:
Dmitri Mendeleev
used patterns to predict undiscovered
elements
Johann Wolfgang Dobereiner
created groups of three elements,
each based on similar properties
John Newlands
arranged elements according to their
atomic mass
Antoine Lavoisier,
divided elements into four categories
✓
Answer:
Two-third of the toxic metal, mercury comes from gold mining.
Explanation:
During gold mining small pieces of gold which are within the soil are separated with the help of mercury. Both gold and mercury are mixed and they forms amalgam. Further gold can be extracted by vaporizing the mercury, thus releasing it into air and contributing to two-third of the air pollution by human activities.
Therefore (d) gold mining is the correct answer.
Answer is: H+ will increase and OH− will decrease.
pH = 11.4.
pH = -log[H+].
[H+] = 10∧(-pH).
[H+] = 10∧(-11.4).
[H+] = 4·10⁻¹² mol/L.
[H+] · [OH-] = 1·10⁻¹⁴ mol²/dm⁶.
[OH-] = 0.0025 mol/L.
pH value (potential of hydrogen - [H+]) is a logarithmic scale that specify the acidity or basicity of an aqueous solution.
When pH is greater than seven, aqueous solution is basic, below seven is acidic and when pH is equal seven, solution is neutral.
B D and E. C isn't the answer because it is stopped.
The rule is number your table 1 2. 3 4 5 6 7 0 the number of shells increase as you go further up as it indicates the number of electrons on the outer shell e.g Argon will have 3 electrons on its outer shell hope this helps if not its then tighttt
