The web site of the Nobel Prize explains that readers who want to inspect the Curies’ notebooks must sign a paper that states that they are aware of the health risks that are involved with handling the notebooks. What health risk is most likely to occur from handling the notebooks? A. excessive coughing
B. anemia
C. muscle cramping
D. swelling of the joints

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.  

answer: cellular respiration takes in food and uses it to create atp, a chemical which the cell uses for energy. usually, this process uses oxygen, and is called aerobic respiration. it has four stages known as glycolysis, link reaction, the krebs cycle, and the electron transport chain.