What element is used as a shield to protect people from radioactive substances?

Numbers with a end value of 4 or lower are rounded up, while with an end value of 5 or higher are rounded down. true or false?

Which change in temperature is the smallest? a change of 1 thomson degree a change of 1 kelvin degree a change of 1 fahrenheit degree a change of 1 celsius degree

Afusion reaction takes place between carbon and another element. neutrons are released, and a different element is formed. the different element is a) lighter than helium. b)heavier than helium. c)the same weight as helium. d)dependent on the element that reacted with carbon.