Answer:
1.42
Explanation: Because 2.12-0.70 equals 1.42
GROUNDWATER is the term used for water that soak into the ground, fills the openings in the soil and trickles into cracks and spaces in rock layers.
Groundwater is usually found underneath the earth surface in the spaces and cracks in sand, rock and soil. It is stored in aquifers. Ground water usually connect with various water bodies such as oceans, rivers and streams and it is always a natural source of water for vegetation. Ground water is a very important natural resource.
The missing element : ₇¹⁴N
<h3>Further explanation</h3>
Given
Reaction
₆¹⁴C ⇒X + ₋₁⁰e
Required
The missing element
Solution
Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
- alpha α particles ₂He⁴
- beta β ₋₁e⁰ particles
- gamma particles ₀γ⁰
- positron particles ₁e⁰
- neutron ₀n¹
In a decay reaction, the sum of the mass number and atomic number before and after the decay is the same.
The element X :
Atomic number = 6 + 1 =7
Mass number = 14 + 0 = 14
Gases can be compressed easily because there is a large amount of space between the individual molecules, which are very active and move around at high speed. When gases are compressed, the particles are forced much closer together, allowing a huge amount of particles to fit a small space.
Answer:
It will take 6.6 hours for 75% of the lead to decay.
Explanation:
The radioactive decay follows first order rate law
The half life and rate constant are related as
The rate law for first order reaction is
![time=\frac{1}{k}(ln[\frac{A_{0}}{A_{t}}]](https://tex.z-dn.net/?f=time%3D%5Cfrac%7B1%7D%7Bk%7D%28ln%5B%5Cfrac%7BA_%7B0%7D%7D%7BA_%7Bt%7D%7D%5D)
Where
A0 = initial concentration = 1 g
At= final concentration = 0.25 g (as 75% undergoes decay so 25% left]
