Question 3
which of the following isotopes is not commonly used for dating objects?
carbon-14
phosphorus-32
potassium-40
rubidium-87

The isotope that is not commonly used for dating objects is Phosphorous-32.

Phosphorous-32 is most commonly found in organic molecules and is mostly used in biochemistry, molecular biology, and medicine. It can be used to track phosphorylated molecules.  

Carbon 14 is an isotope that is used while determining and finding the age of old and ancient objects. Meanwhile, Potassium 40 is an isotope that is used in determining the age of minerals and rocks. Also, Rubidium 87 is a rubidium element isotope that is used for determining and dating the age of rocks. Only Phosphorous 32 is not used for dating objects out of the four isotopes.  

hello there,

igneous rock formed from below the surface would have more crystals because

answer: because magma cools more slowly than lava

a fossil fuel is a fuel formed by natural processes, such as anaerobic decomposition of buried dead organisms, containing energy originating in ancient photosynthesis.[1] the age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years.[2] fossil fuels contain high percentages of carbon and include petroleum, coal, and natural gas.[3] other commonly used derivatives include kerosene and propane. fossil fuels range from volatile materials with low carbon to hydrogen ratios like methane, to liquids like petroleum, to nonvolatile materials composed of almost pure carbon, like anthracite coal. methane can be found in hydrocarbon fields either alone, associated with oil, or in the form of methane clathrates.

the theory that fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the earth's crust over millions of years was first introduced by andreas libavius "in his 1597 alchemia [alchymia]" and later by mikhail lomonosov "as early as 1757 and certainly by 1763".[4] the first use of the term "fossil fuel" was by the german chemist caspar neumann, in english translation in 1759.[5]

in 2017 the world's primary energy sources consisted of petroleum (34%), coal (28%), natural gas (23%), amounting to an 85% share for fossil fuels in primary energy consumption in the world.[6] non-fossil sources in 2006 included nuclear (8.5%), hydroelectric (6.3%), and others (geothermal, solar, tidal, wind, wood, waste) amounting to 0.9%.[7] world energy consumption was growing at about 2.3% per year. in 2015 about 18% of worldwide consumption was from renewable sources.[8]