What happens to the nucleus of an atom when the atom is involved in a chemical reaction?

What is avogadro’s number, and why is it useful

This drawing shows a human body system. what is the primary function of this body system?

Abeaker with 2.00×102 ml of an acetic acid buffer with a ph of 5.000 is sitting on a benchtop. the total molarity of acid and conjugate base in this buffer is 0.100 m. a student adds 4.70 ml of a 0.360 m hcl solution to the beaker. how much will the ph change? the pka of acetic acid is 4.740.