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.
If theres a mixture of components we can calculate the mole fraction
mole fraction can be calculated as follows
mole fraction of component =
![\frac{number of moles of component}{total number of moles of all components }](https://tex.z-dn.net/?f=%20%5Cfrac%7Bnumber%20of%20moles%20of%20component%7D%7Btotal%20number%20of%20moles%20of%20all%20components%20%7D%20)
number of moles of ethanol - 3.00 mol
total number of moles in mixture - 3.00 + 5.00 = 8.00 mol
mole fraction of ethanol =
![\frac{3.00 mol}{8.00 mol }](https://tex.z-dn.net/?f=%20%5Cfrac%7B3.00%20mol%7D%7B8.00%20mol%20%7D%20)
mole fraction of ethanol is 0.375
Answer:
An independent variable is a variable (often denoted by x ) whose variation does not depend on that of another.
Answer: 2.23 is the difference.
Explanation: Sodium has an electronegativity of 0.93 and Chlorine has an electronegativity of 3.16, so when Sodium and Chlorine form an ionic bond, in which the chlorine takes an electron away from sodium, forming the sodium cation, Na+, and the chloride anion, Cl-.