Answer:
See below
Step-by-step explanation:
(a) Shape
The formula for water is H-O-H.
The central O atom has four electron pairs around it. They try to get as far from each other as possible, so they point toward the corners of a tetrahedron.
Only two of the pairs have a hydrogen atom attached, so water has a bent shape. The H-O-H bond angle is about 104°.
(b) Chemical magnet
The O atom has a greater attraction than H for the shared electrons in the O-H bonds, so the electrons spend more time near the O.
This gives the O atom a partial negative charge (pink in the diagram) and the H atoms a partial positive charge (blue).
The water molecule acts like a chemical magnet because its negative end attracts the positive ends of other molecules, while its positive ends attract the negative ends of other molecules.
anything except for a and d
Answer:
homeostasis
Explanation:
source Wiki
In biology, homeostasis (or “health”) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these variables is controlled by one or more regulators or homeostatic mechanisms, which together maintain life.
Just divide 2.50*10^25 by 6.02×10^23 to get to moles