Which of these is the best evidence that a chemical reactions occurs when coal burns? A-Coal is made up of more than one element
B-a new substance is produced
C-Oxygen is present
D-The shape of coal changes

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true

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.

Glucose (c6h12o6) is an important biological molecule. (round the answer to nearest hundredth.) what is the percent by mass of carbon in glucose?