Answer:
The noble gases with complete outermost shell electrons.
Explanation:
Noble gases or inert gases do not react chemically with other elements because they have a complete configuration of their electronic shells. What drives chemical reaction is simply the exchange of electrons between two or more atoms. It can be a loss, a gain or simple sharing of electrons in order to achieve a complete configuration just like those of noble gases.
A drop of iquid mercury is D. <span> a pure substance and an element. This is because mercury is an element which exists as liquid in the normal or standard conditions. It is a metal that is toxic to all environments. It is pure because it is composed only of one kind of substance.</span>
Decreasing the activation energy needed for the reaction.
Answer:
Stomata and guard cells facilitate this job of gas exchange in plants. Here, the guard cells are parenchyma cells, and they are the cells that surround stomata. Guard cells control transpiration, which is an essential process of plants that keep plants healthy.
Explanation: