b. A student has an 80 g sample of a radioactive material that has a half-life of 20 seconds. How much material will he have left after one minute? c. Given the periodic table below, write a beta decay equation for the transmutation of a radioactive isotope of Rutherfordium, which has 104 protons and 183 neutrons. Periodic Table of Eleme tra esde noa 1 2 3 4 5 7 9 10 11 12 13 14 15 16 17 18 1H Symbol Sold Nonmetals Metals

A quart of water weighs 7.1 lb.  Determine its mass(kg) Choices are: A. 32.3 B. 1.23 C. 3.33 D. 3.23

8. Ả = − 1î – 2ĵ, B = 2î – 1ĵ, calculate the cross product of Ả X B.

DD =25i need help to do it correctly the solution answered is available and even the answers for 25th in table i just need explanationhow to do it?  please thank you!          M person 80 kg safe m ladder 30 kg caution       unsafe L/3 mass fraction     0.37878788               L mass fraction     0.86363636               Nfloor  1078 N   Nwall max 270 N available Ff max 270 N available                 L/3 way up the ladder   top of ladder   DOB Theta deg radians   Tan theta Cot theta   mu required Ff required mu required Ff reqd   25 80 1.3962634   6 0.17632698   0.0668 72.0   0.1523 164.2