The elements in the periodice table are not listed in alphabetical order, because the arragement in rows (periods) and columns (groups or familes), in increasing order of atomic number (number of protons of the atoms) permits to explain similarities among the elements, trend in some properties, and even predict properties of unknown elements.
For example, the elements of the first group (family), called alkaline metals, all have 1 valence electron, have similar physical properties (ductibility, malleability, luster, thermal and electricity conductivity), react in similar way with water, show a trend in the atomic radii and in the ionization energy.
You can tell similar stories for other groups like, alkalyne earth metals, halogens and noble gases.
You can also tell trends in electroneativities, and atomic radii, for a row of elements, as per the order they are in the row.
So, the current array resulted very helpul for chemists to explain and predict the behavior and properties of the elements.
According to Arrhenius Theory of acids and bases, an Arrhenius base, when dissolving in water, produces the only negative ion: OH-.
Therefore, (3) OH- is the correct answer.
Hope this is helpful~
Answer:
32.23 to 4 significant figures.
Explanation:
The molar mass of the element is the mass of 6.022 * 10^23 atoms (Avogadro's number).
So by proportion it is 6.022 * 10^23 * 3.88 / 7.25 * 10^22
= 32.23 to 4 significant figures.
I believe it was John Newlands.
Hope that helped
<u>Answer:</u> The mass of HCl present in 500 mL of acid solution is 36.5 grams
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:
where,
are the n-factor, molarity and volume of acid which is HCl
are the n-factor, molarity and volume of base which is NaOH.
We are given:
Putting values in above equation, we get:
To calculate the mass of solute, we use the equation used to calculate the molarity of solution:
Molar mass of HCl = 36.5 g/mol
Molarity of solution = 2 M
Volume of solution = 500 mL
Putting values in above equation, we get:
Hence, the mass of HCl present in 500 mL of acid solution is 36.5 grams
