Answer:
Option A
Explanation:
Leguminous plants like pulses etc. have root nodules comprising of rhizobacterium which live in a symbiotic relationship with the roots of the plant and in turn fix the nitrogen in the soil in the roots of the leguminous plants.
Hence, option A is correct
Q: What is the change of entropy for 3.0 kg of water when the 3.0 kg of water is changed to ice at 0 °C? (Lf = 3.34 x 105 J/kg)
Answer:
-3670.33 J/K
Explanation:
Entropy: This can be defined as the degree of randomness or disorderliness of a substance. The S.I unit of Entropy is J/K.
Mathematically, change of Entropy can be expressed as,
ΔS = ΔH/T ....................................... Equation 1
Where ΔS = Change of entropy, ΔH = heat change, T = temperature.
ΔH = -(Lf×m).................................... Equation 2
Note: ΔH is negative because heat is lost.
Where Lf = latent heat of ice = 3.34×10⁵ J/kg, m = 3.0 kg, m = mass of water = 3.0 kg
Substitute into equation
ΔH = -(3.34×10⁵×3.0)
ΔH = - 1002000 J.
But T = 0 °C = (0+273) K = 273 K.
Substitute into equation 1
ΔS = -1002000/273
ΔS = -3670.33 J/K
Note: The negative value of ΔS shows that the entropy of water decreases when it is changed to ice at 0 °C
Answer:
The range of atoms = (30-300 pm) depending upon the element
Explanation:
The Atomic radii of the atom is the distance from the center of the circle to the outermost orbital.
The center of the circle is the nucleus and the radii is the outermost boundary.
The actual size of the atom is decided on the basis of the Zeff . Also known as <em>effective nuclear charge.</em>
<em>Zeff: It is the net positive charge felt by the outermost electron by the nucleus.</em>
<em>The value of Zeff depends upon the shielding constant. More the shielding less will be the Zeff . Hence the size of the atom increases.</em>
Due to shielding the outermost electrons feel less pull of nucleus.
<em>The greater the Zeff , the smaller the radius of the atom.</em>
The formula used to calculate the atomic mass is :
pm
Here "pm"= picometers
<u>The size of the smallest atom H-atom = 120 pm</u>
<u>The range of atoms = (30-300 pm)</u>
<span>Osmotic pressure is the minimum amount of pressure a solution must exert in order to prevent from crossing a barrier by osmosis. Solute molecules have difficulty crossing semipermeable membranes, so the more solutes that are in a solution, the higher the osmotic pressure will be.
Between 30% sucrose and 60% sucrose, 60% sucrose will have a greater osmotic pressure than 30% because it has a higher percentage of solutes. However, since sucrose has a higher potential to cross semipermeable membranes and is more absorbable than magnesium sulfate, magnesium sulfate would have a higher osmotic pressure than 60% sucrose even though 60% sucrose has higher molecules.</span>
Answer:
D: a new substance
Explanation:
Chemical reaction
A change in matter that produces on or more new substances
