Answer: A. need the same number of electrons to fill their valence shells
B. have the same number of valence electrons
Explanation:
Elements are distributed in groups and periods in a periodic table.
Elements that belong to same groups will show similar chemical properties because they have same number of valence electrons.
Example: Flourine, chlorine and bromine are elements which belong to Group 17. They have 9, 17 and 35 electrons respectively and contain 7 valence electrons each and need one electron to complete their octet.
The chemical reactivity of elements is governed by the valence electrons present in the element.
It's true
work measure by joule.
Energy = work/time
= joule/s .
and joule/s represents watt
Eastward rides = 7+5 = 12 miles
Northward rides = 2+3 = 5 miles
This forms a right angled triangle.
The resultant triangle has legs with 12 mi and 5 mi. The hypotenuse is the resultant. Then,
Resultant = Sqrt (12^2+5^2) = 13 mi
The angle formed by the resultant to the east direction is given by:
Sin Ф = 5/13 => Ф = Sin ^-1 (5/13) = 22.62°
The correct answer is given by option 1: magnitude = 13.0 mi; direction = 22.6° North of East.
When amplitude of motion increases to 2a the time period remains the same.
The formula for spring mass system is given by
T = 2π√m/k
where, k = spring constant
m= mass of spring
T = time period
So, from here we get to know that time period is independent of amplitude, so we increase or decrease the amplitude of system there will be no effect on Time period of spring mass system.
Thus, when amplitude of motion increases to 2a the time period remains the same.
Learn more about spring mass system here:
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I believe it's in Newtons which has the symbol N