Answer: Selectivity of mineral nutrients absorbed by roots
Explanation:
The Casparian strip in the plants are waxy coating found in the roots of the plant which helps in absorbing excess of water into the plants.
These strips thickens the walls, thus preventing the excess of soil solution from being pulled by the roots into the central part of the plant.
It helps in selecting the type and amount of nutrient into the plant but the plant having no Casparian strip will reduce the selectivity of the nutrients.
Answer:
C₈H₈O₃
Explanation:
The empirical formula is the simplest whole-number ratio of atoms in a compound.
The ratio of atoms is the same as the ratio of moles.
So, our job is to calculate the molar ratio of C:H:O.
Assume 100 g of the compound.
1. Calculate the mass of each element.
Then we have 63.15 g C, 5.30 g H, and 31.55 g O.
2. Calculate the moles of each element
3. Calculate the molar ratio of the elements
Divide each number by the smallest number of moles
C:H:O = 5.258:5.258:1.972 = 2.667:2.666:1
4. Multiply by a number to make each ratio close to an integer
Multiply the ratios by three.
2.667:2.666:1 = 8.000:8.000:3 ≈ 8:8:3
5. Write the empirical formula
EF = C₈H₈O₃
The angle of incoming sunlight varies at different places.
Answer:
I,II, III
Explanation:
Firstly, the magnitude of nuclear charge affects the first ionization energy of an element. Hence,as effective nuclear charge increases, the attraction between the nucleus and the outermost electron increases and ionization energy consequently increases. Thus Mg has a higher first ionization energy than Be.
Secondly, oxygen has an electron configuration of 1s2 2s2 2p4 while nitrogen has an electron configuration of 1s2 2s2 2p3. Now, recall that extra energy is often associated with half filled orbitals hence nitrogen has a higher first ionization energy than oxygen. Furthermore, the addition of electron to an already half filled 2p orbital in oxygen (pairing) leads to inter electronic repulsion and drastic fall in first ionization energy. Therefore, as we move from nitrogen to oxygen in the periodic table, greater inter-electron repulsion between two electrons in the same p-orbital counter balances the increase in effective nuclear charge hence nitrogen has a greater first ionization energy than oxygen.
Lastly, the 3p orbital is far away from the nucleus hence we expect it to feel less of nuclear attraction than a 2p orbital. Hence the first ionization energy of Ar is less than that of Ne.