How is a pure substance different from a mixture? a: a pure substance is heterogeneous b: a mixture is made of one substance c: mixtures cannot be separated by physical means d: pure substances cannot be separted by physical means

Which equation represents a fission reaction? o "9n+h—150 o 235u + n—190cs + rb+25 o be + he—1c + in o 28 np —> 2390 pute

Which of the following did jj thompson discover about atoms? a)an atom has an internal structure. b) atoms are tiny indivisible particles. c)electrons orbit the nucleus of an atom. d) the nucleus of an atom contains protons and neutrons.

What method(s) do plants use to obtain nitrogen? select all that apply. absorb it from the atmosphere use bacteria to convert nitrogen to usable form obtain usable nitrogen compounds from the soil absorb nitrogen from water taken in at the roots