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:
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
Hope this helps you
Answer:
High activation energy is the reason behind unsuccessful reaction.
Explanation:
There are two types of reaction: (1) thermodynamically controlled reaction and (2) kinetically controlled reaction.
Thermodynamically controlled reaction are associated with change in enthalpy during reaction. More negative the enthalpy change, more favored will be the reaction.
Kinetically controlled reaction are associated with activation energy of a reaction. The lower the activation energy value, the more rapid will be the reaction.
Here, reaction between 
and 
is thermodynamically favored due to negative enthalpy change but the high activation energy does not allow the reaction to take place by simple mixing.
