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.
Answer:
According to the modern periodic law, the properties of the elements and their compounds are a periodic function of their atomic numbers. Thus, in the modern periodic table, atomic number forms the basis of the classification of elements;The modern table is called 'long form' of the periodic table.
hope this helps
Answer:
6 neutrons
Explanation:
6 neutrons
Boron having an atomic number of 5 means that it will have 5 protons. 11 atomic mass units in total. Neutrons also have a atomic mass unit of 1. So there are 6 neutrons
Answer:
The equilibrium position will shift towards the lefthand side.
Explanation:
[CoCl4] 2- (aq) + 6H2O (l) ⇌ [Co(H2O)6] 2+ (aq) + 4 Cl- (aq)
The equation written above in exothermic as written. That is, the forward reaction is exothermic. The equilibrium position is observable by monitoring the colour change of the solution. At the left hand side, the solution is blue but at the right hand side the solution is pink. Addition of heat (in a hot water bath) will shift the equilibrium towards the left hand side, that is formation of more [CoCl4] 2- making the solution to appear blue in colour.
