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=

Alarge marble is dropped in a graduated cylinder with 35ml of water in it.the water level increases to 49ml.what is the volume of the marble

16. why must the number of electrons lost equal the number of electrons gained in every redox reaction? use 3 – 4 sentences in your own words to address this question. 18. what type of radiation is emitted when chromium-51 decays into manganese-51? show the nuclear equation that leads you to this answer. 19. a radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. what was the identity of the original nucleus? show the nuclear equation that leads you to this answer.

Displacement is the slope of a velocity vs. time graph a. true b. false