Answer:
Valency is defined as the number of hydrogen atoms which combine directly or indirectly with one atom of an element.
Example:
One atom of nitrogen combines with three atoms of hydrogen to form ammonia gas. So, the valency of nitrogen is 3.
Answer:
Explanation:
Isotopes are atoms of elements that have the same atomic number but different mass number hence ISOTOPY. Radioactive Isotopes on the other hand are unstable as they either undergo Alpha decay, beta decay or gamma decay compared to stable isotopes.
Radioactive elements decay at varyinf rates as such the rate of radioactive decay is used in the characterization of radioactive element and mostly expressed in terms of the half life of the radioactive elements.
Half life is the time taken for half of the total atoms of an elements to decay into half of its initial sizes. for example, the half life of radium-226 is 1622 years, it implies that if we have 1000000 radium atoms at the beginning, then at the end of 1622years, 500000 would have disintegrated. These phenomenon can never be experienced by stable isotopes as such they can not be used in carbon dating techniques. reason why uranium-238 is mostly and commonly used in the earth crust to estimate the ages of rocks because it has a half life of 4.5 x 10^9 years.
And also, the radioactive isotopes of most common light element are short, they have very short half life (few days or weeks) and they decay rapidly to vanshing point, as such, they are not found in nature to any reasonable extent.
C
Speed is the time rate at which Sue covers the distance. It is derived by dividing the total distance covered by the total time taken to cover the distance . Usually SI unit for speed is km/h or mph or m/s.
Explanation:
Speed is also referred to as velocity- so the two are synonymous.
Acceleration is the rate at which speed is increasing. It is usually given by SI unit m/s². The opposite of acceleration is deceleration which is the rate at which speed is decreasing.
Distance is the measurement, in meters of kilometers or miles or yards..etc, that has been covered from one point to another.
Learn More:
For more on speed, velocity, distance and acceleration check out;
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Answer:
As you move across a period, the atomic mass increases because the atomic number also increases. ... The atomic mass for any given atom mainly comes from the mass of the protons and neutrons.
Explanation:
