I remember learning this last y’all i jus don’t remember it might be A or C
Answer:
I want to say option C: Testing which surfa e is easier to slide a wooden block across.
Explanation:
I'm not 100 % sure though with my answer. I'm truly so very sorry if my answer is wrong. I tried my best.
Answer:

Explanation:
The work function of the sodium= 495.0 kJ/mol
It means that
1 mole of electrons can be removed by applying of 495.0 kJ of energy.
Also,
1 mole =
So,
electrons can be removed by applying of 495.0 kJ of energy.
1 electron can be removed by applying of
of energy.
Energy required =
Also,
1 kJ = 1000 J
So,
Energy required =
Also,
Where,
h is Plank's constant having value
c is the speed of light having value
So,
Also,
1 m = 10⁻⁹ nm
So,

Answer:
There have been seven horizontal rows of elements are called phases in the periodic table of elements. Groups, or families, are called vertical columns of elements. Metals, – anti, and metals are the most common ways of classifying the periodic table.
Explanation: