1,38×10²² = 0,138×10²³
0,138×10²³ ----- 1,5g
6,02×10²³ ------ X
X = (1.5×6,02×10²³)/0,138×10²³
X = 65,435 g/mol
It's ZINC (Zn)
:•)
Answer:
Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity
Explanation:
Altitude is height above sea level. The density of air decreases with height. There are two reasons, at higher altitudes there is less air pushing down from above,and gravity is weaker farther from earths center.
Answer:
Explanation:
Actinoids are the series have 15 element in the periodic table.
Chemistry of actinoids are complicated because of the following reasons.
- Their outer most orbitals are 6d and 7s but most of the electrons resides in 5f orbitals. These orbitals are most exposed to environment and incoming electron picked up by 5f orbital instead of 6d or 7s orbitals.
- They are radioactive elements that couldn't be handle in normal condition to study their properties.
- Their f-orbital can accommodate 14 electrons and they have many variable oxidation state.
- 5d electron donot contribute in the formation of chemical bonds.
- They have a very strong tendency to make complexes
- Most of the actinoides are artificial and are in very minute in amount. they are in very less quantity that is amounts found in nano-grams so are more expensive too and
- As they are radioactive so their half life is very short and in very less time the decay occur so couldn't be study as upon decay their actual properties changed.
Due to all the above reasons it make difficult for a chemist to study about the chemical properties of actinoids.
<h3>
Answer:</h3>
63 years
Eighth
The number of half lives
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Explanation:</h3>
It will take 63 years for half of the sample to decay
In 189 years, eighth of the sample will be left
Scientists can figure out how old a sample is by multiplying the number of half lives by the length of the half life.
Half life is the time taken by a radioactive sample to decay to half of the original amount.
Therefore, for a radioactive element with a half-life of 63 years, it will take 63 years for the sample to decay to half of the original amount.
After 189 years, only an eighth of the sample will be left.
That is, 189 years is equivalent to 3 half-lives
Therefore, if the original amount is 1, then;
1 → 0.5 → 0.25 → 0.125
Thus, scientists can figure out how old a sample is by multiplying the number of half lives by the length of the half life.
