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
moles CO₂ = 5.57.10⁻⁴
<h3>Further explanation
</h3>
A mole is a number of particles(atoms, molecules, ions) in a substance
Can be formulated :
0.7% percent change with 3.5g of plant matter
mass :
moles :
<span>When water decomposes into oxygen and hydrogen, the mass "Remains Constant" as according to Law of Conservation of mass, mass can neither be created not destroyed,.
In short, Your Answer would be Option A
Hope this helps!</span>
Pretty sure it’s 2, increase in strength of hurricanes
