Ka for weak acids is ---> Ka= (X)²/ (initial- X)
initial= 0.0400 M
to find X, you can find the H concentration using pH
[H+]= 10^-pH
[H+]= 10^-1.80= 0.016 which is X
ka = (0.016)²/ (0.0400 - 0.016) = 0.011
The number of valence electrons = group number
e. g 1 valence electron in group IA
Answer:
3
Explanation:
102 are significant figures
Answer:
17. D. Chemical change
18. C. Cell wall
19. D. To transfer matter and energy within and between organisms.
20. A. Transporting materials
21. C. Carbon dioxide
22. A. Cellular respiration
23. C. Produce food and give off oxygen
Explanation:
I have been able to supply the correct answers. The cell wall functions as a structure that provides structural support and protection to the cell. It is tough, flexible and at times rigid. In a chemical change, new materials with new properties are manufactured. So, the process of photosynthesis is a chemical change.
The endoplasmic reticulum actually transports material. It transports materials like protein and lipids made within the cell and sends it to where they are needed.
Carbon dioxide is the the gas that animals give off and plants use it during photosynthesis. Cellular respiration involves the activities that result to the breaking down of food in order to release energy.
