C. air, fire, water, earth. 4 elements
Answer:
The elements become less reactive.
Explanation:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction and reactivity increases because of greater electron affinity.
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased. The electron affinity decreases because of shielding effect and thus atom become less reactive.
Latent heat of melting is the energy that a solid absorbs to change its phase as its liquid. During this process, since all energy is used to change the phase, the temperature is constant.
Here the latent energy of melting for 1 g of ice is 80 calories and that 1 g of ice only absorbed 60 calories. hence the phase is not changed because it requires more 20 calories to melt.
Hence 1 g of ice remains as its solid phase (ice).
Answer: Neutral Value
Explanation: pH of the blood is maintained at 7.0 to 7.5that is neutral value.
This is because if the pH of the is lower than the maintained value then it will become acidic .
Acidic pH can cause the medical urgency known as acidosis leading to vomiting, diarrhea etc.
If the pH becomes higher, then the blood will become basic in nature and it can also leas to the death of the person.
That is why the pH of the blood is maintianed at neutral value of 7.0 to 7.5
