If new evidence or observations falsify a scientific theory, the theory will have to be changed to adapt to the new data or just discarded altogether.
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
The amount of energy released when 0.06 kg of mercury condenses at the same temperature can be calculated using its latent heat of fusion which is the opposite of melting. Latent heat of fusion and melting can be used because they have the same magnitude, but opposite signs. Latent heat is the amount of energy required to change the state or phase of a substance. For latent heat, there is no temperature change. The equation is:
E = m(ΔH)
where:
m = mass of substance
ΔH = latent heat of fusion or melting
According to data, the ΔH of mercury is approximately 11.6 kJ/kg.
E = 0.06kg (11.6 kJ/kg) = 0.696 kJ or 696 J
The answer is D. 697.08 J. Note that small differences could be due to rounding off or different data sources.
Answer:
Compound 1 is molecular
Compound 2 is ionic
Compound 3 can't really be decided
Explanation:
A molecular substance does not conduct electricity, has very low melting and boiling points and is held together by very weak intermolecular forces.
An ionic substance conducts electricity in solution or in molten state but never in the pure solid state, has a high melting and boiling point and has a dull appearance most times.
Compounds 1 shows the properties of molecular substances hence it are designated as such.
On the other hand, compound 2 shows the properties of an ionic substance and is also designated as such.
We can't really decide on compound 3 because it shows some properties of ionic substances and some properties of molecular substances.
