Cobalt-60 has a half life of 5.25 years. If you started with a 40 gram sample of pure cobalt-60, how many grams of cobalt-60 would remain after 10.5 years?

Is there any relation between distance and the colors we see?

How do you tell whether or not velocity is changing?

One isotope of sodium has 11 protons and 7 neutrons. What is the mass number of this isotope?

What are the si units for average speed?

How does the moons diameter compare with the distance between the earth and the moon?

Which property of gold is a physical property? A. ability to bond B. reactivity C. ability to rust D. malleability

On a spring break vacation you decide to visit the grand canyon near flagstaff, arizona. then you head south to visit some friends in phoenix, arizona. while on the drive you notice that the temperature is increasing along the route.

An object weighing 1.840 kg has a volume of 0.0015 m3. What is the density of the object in g/cm3?

What is the purpose of cooking using sunlight?

Two planets of the same mass are observed. Which of the following distances between the two planets would result in the least gravitational attraction? A. 90 light years B. 80 light years C. 60 light years D. 50 light years