Answer:
Work = 90.65 j
Explanation:
Given data:
Mass = 0.500 Kg
Distance = 18.5 m
Work done = ?
Solution:
Work = force . distance
Force = mg
Work = mg.distance
Work = mgh
Work = 0.500 Kg × 9.8 m/s²× 18.5 m
Work = 90.65 Kg .m²/s²
Kg .m²/s² = j
Work = 90.65 j
The half-life of carbon-14 is about 5730 years
Answer : (C) Hafnium is the most likely identity of the given substance.
Solution : Given,
Mass of given substance (m) = 46.9 g
Volume of given substance (V) = 3.5 
First, find the Density of given substance.
Formula used :

Now,put all the values in this formula, we get
= 13.4 g/
So, we conclude that the density of given substance (13.4 g/
) is approximately equal to the density of Mercury and Hafnium (13.53 and 13.31 g/
respectively).
According to the question the substance is solid at room temperature but Mercury is liquid at room temperature. So, Mercury is not identical to the given substance.
Another element i.e, Hafnium is the element whose density is approximately equal to the given substance and also solid at room temperature. And we know that the melting point of solid is high.
So, Hafnium is the most likely element which is the identity of the given substance.
Answer:
Billions in the known universe!
Explanation:
Because there are approximately 100 billion galaxies in the observable universe.
Hope it helps!
Acids react with calcium carbonate and more specifically carbonate to form carbon dioxide. An acid will give protons to the carbonate anion to produce carbonic acid which then decomposes into carbon dioxide and water. I hope this helps. Let me know if anything is unclear.