Explanation:
first one because absolute dating is a thing for rock layers
Answer:
2x1000 = 2000
Explanation:
10^3 = 10×10×10 = 1000
exponent , the ^3 means multiply the number by itself 3 times, if it was ^4, it would be 4 times and so forth.
another trick for 10s is just put the 1 and the exponents number of 0's after the 1. so in this case, put three 0's: 1,000
Convalent Bond energy is low
Cs -137 has a half life of about 30 years. If 60 years pass, there is two half lives passed so 1/2 * 1/2= 1/4. Take 1/4 and multiply it with the mass given:
(1/4)*20mg=5mg left