Need serious hep no JOKE so plz help me List the % by mass for each element:
First, add the total mass of 4 atoms of hydrogen, plus 2 atoms of carbon, plus 2 atoms of oxygen. Total mass = . To obtain percent by mass, divide the mass of each element by the mass of the total:

H=
C=
O=

What is the maximum number of electrons that an atomic orbital can contain?

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

Imagine that twenty i. u.’s of enzyme z were catalyzing the above reaction for one minute, under vmaxconditions, in a 3.00 ml assay volume. the assay is buffered with 20 mm phosphate buffer, ph 7.60. what will the ph be at the end of that one minute?