Answer:
Elements having same valence electrons are placed in <u>same group.</u>
Explanation:
First, let's start with some basic concepts of modern periodic table:
1. Modern Periodic table : It is the arrangement of element in the increasing order of their atomic numbers
The Modern periodic table is divided into Periods and groups .
Periods : These are the horizontal rows. There are seven periods in the periodic table . Period 1 has 2 element. Period two and three has 8 elements , period 4 and 5 have 18 elements and the period 6 and 7 have 32 elements.
Same period have same number of atomic orbital(Shell)
Group : The group is the vertical columns . There are 18 groups in the modern periodic table.Those element which have same group number will also have same number of electron in their outermost shell. The number of electron in the outermost shell determines the valency of the element.
So, elements showing same valency are placed in same group.
All alkali are place in group 1 and have 1 valance electron in the outermost shell
In 1869 he published a table of the elements organized by increasing atomic mass.
Mendeleev is called the "father of the modern periodic table
stated that if the atomic weight of an element caused it to be placed in the wrong group, then the weight must be wrong. (He corrected the atomic masses of Be, In, and U)
was so confident in his table that he used it to predict the physical properties of three elements that were yet unknown.
After the discovery of these unknown elements between 1874 and 1885, and the fact that Mendeleev's predictions for Sc, Ga, and Ge were amazingly close to the actual values, his table was generally accepted.
However, in spite of Mendeleev's great achievement, problems arose when new elements were discovered and more accurate atomic weights determined.
STOP DELETING MY COMMENTS PEOPLE PLEASE!!!!!!!!!
Increase in Oxygen shift the equilibrium towards reactant side.
<u>Explanation:</u>
6CO₂ + 6H₂O ⇄ C₆H₁₂O₆ + 6O₂
This is the reaction occurs in the photosynthesis of plants by means of sunlight. In this case, if the concentration of Oxygen increases or adding more oxygen to the product side will shift the equilibrium towards the reactant side according to the Le Chatlier's principle, which adjusts the equilibrium by itself for any changes that is increase or decrease in pressure, temperature or concentration of reactants or products.
Answer:
All other units are gotten from them
155,500
I did this to the best of my ability. I have a hard time comprehending things sometimes so I’m so so so sorry if it’s wrong
