<span>In this demonstration, there is a single compass and a piece of wire that is perpendicular to the plane that the compass sits on. The wire with current flowing through it can alter the direction the compass needle points.</span>
<u>First Symbol </u>: Cobalt (Co)
Its Group Number - 9
Its Period Number - 4
Its Family Name - Transition Metal
<u>Second Symbol</u> : Silicon (Si)
Its Group Number - 14
Its Period Number - 2
Its Family Name - Semiconductor
<u>Third Symbol</u> : Astatine (At)
Its Group Number - 17
Its Period Number - 6
Its Family Name - Halogen
<u>Fourth Symbol </u>: Magnesium (Mg)
Its Group Number - 2
Its Period Number - 3
Its Family Name - Alkaline Earth Metal
<u>Fifth Symbol</u> : Xenon (Xe)
Its Group Number - 18
Its Period Number - 5
Its Family Name - Noble Gas
Answer:The frequency of the echo is slightly decreased
Explanation:
Given
speed of boat 
cliff is
away
when boat is still , suppose t is the time taken by the echo to reach observer on the boat
But as soon as boat starts moving the distance between cliff and boat decreasing and time for echo to reach observer also decreases
and we know 
therefore frequency of the echo slightly decreased.
Answer : Zamir's displacement and Talia's displacement is equal.
Explanation :
Displacement is explained to be the changing position of an object.
Zamir covers total distance 27 m and Talia covers total distance 19 m but Zamir's initial and final position and Talia's initial and final position is same.
So, we can say that Zamir's displacement and Talia's displacement is equal.