My apologies, I don’t seem to understand the question.
Answer:
D. Phototropism
Explanation:
Plants, like every other living organism, responds to external stimulus. In this question, the stimulus is LIGHT from the sun entering through the window sill. The plant is responding positively to the light stimuli by growing towards the direction where the light is coming from. This exhibit is called PHOTOTROPISM.
Phototropism, comes from two words viz photo- meaning light and tropism- meaning movement. Hence, phototropism is the growth of an organism (plant in this case) in response to a light stimulus. The case described in this question is POSITIVE PHOTOTROPISM because the growth occurs towards the light source.
1 mole of h3bo3...........6.023*10²³ each h and B and 0 so we will have 3hydrogen+ 1 B+3 oxygen = 7*6.023*10²³ atoms
1 mole .......7*6.023*10²³atoms
4 moles ........x atoms
x=4*7*6.023*10²³.
<u>Answer: </u>The correct statement is X is the effective nuclear charge, and it increases across a period.
<u>Explanation:</u>
We are given that:
X = number of protons − number of core electrons
Effective nuclear charge is defined as the actual nuclear charge (Z = number of protons) minus the screening effect caused by the electrons present between nucleus and valence electrons. These electrons are the core electrons.
The formula used for the calculation of effective nuclear charge given by Slater is:

where,
= effective nuclear charge
Z = atomic number or actual nuclear charge or number of protons
= Screening constant
The effective nuclear charge increases as we go from left to right in a period because nuclear charge increases with no effective increase in screening constant.
Hence, the correct answer is X is the effective nuclear charge, and it increases across a period.
Answer:
a mixture is a material made up of two or more different substances which are physically combined.