Answer:
Q = 1461.6 J
Explanation:
Given data:
Mass of ice = 36 g
Initial temperature = -20°C
Final temperature = 0°C
Amount of heat absorbed = ?
Solution:
specific heat capacity of ice is 2.03 j/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = T2 - T1
ΔT = 0°C - (-20°C)
ΔT = 20°C
Q = 36 g ×2.03 j/g.°C×20°C
Q = 1461.6 J
There must be effective collisions between the reacting chemical particles in order for the chemical reaction to occur.
Answer:
Both answer choice 2 and answer choice 3 are correct choices.
Explanation:
Biotic factors are living components in an ecosystem. They are living organisms which affect another living component in an ecosystem.
Antibiotic factors are non living components of an ecosystem. They are chemicals which affect living organisms.
The choice 2 is correct. The seeds spread out by mice is a biotic factor interacting with an antibiotic factor
Choice 3 is correct. The seeds in the soil grow into new trees are biotic factors interacting with an antibiotic factor
There are two naturally occurring isotopes of gallium: mass of Ga-69 isotope is 68.9256 amu and its percentage abundance is 60.11%, let the mass of other isotope that is Ga-71 be X, the percentage abundance can be calculated as:
%Ga-71=100-60.11=39.89%
Atomic mass of an element is calculated by taking sum of atomic masses of its isotopes multiplied by their percentage abundance.
Thus, in this case:
Atomic mass= m(Ga-69)×%(Ga-69)+X×%(Ga-71)
From the periodic table, atomic mass of Ga is 69.723 amu.
Putting the values,
Thus,
Rearranging,
Therefore, mass of Ga-71 isotope is 70.9246 amu.
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.
