Answer:
Explanation:
No of atoms of Ra in 1 g of sample = 6.023 x 10²³ / 226
N = 2.66 x 10²¹
disintegration constant λ = .693 / half life
half life = 1620 x 365 x 60 x 60 x 24 = 5.1 x 10¹⁰ s
disintegration constant λ = .693 / 5.1 x 10¹⁰
radioactivity dn / dt = λN
= (.693 / 5.1 x 10¹⁰ ) x 2.66 x 10²¹
= .3614 x 10¹¹ per sec
= 3.614 x 10¹⁰ / s
Answer:
, it will sink
Explanation:
The density of an object is given by

where
m is the mass of the object
V is its volume
For the body in the problem, we have
m = 4 kg = 4000 g

Therefore, its density is

And the object will sink in water, because its density is larger than that of water, which is
. (an object sinks when its density is larger than that of water, otherwise it floats).
Answer:
Explanation:
Pluto is a dwarf planet that lies in the Kuiper Belt, an area full of icy bodies and other dwarf planets out past Neptune. Pluto is very small, only about half the width of the United States and its biggest moon Charon is about half the size of Pluto