1) 100s of millions of years ago Trees and plants fall into swamps
2) Layers of rotting plant matter builds up underwater
3) Over millions of years the weight of layers heat the plant matter and turn into Peat
4) Over millions of years more pressure and heat turns Peat into coal
Many angiosperm species rely on the interaction between animals and their flowers for reproduction. As insects, birds or other animals move from one flower to another feeding on nectar, they commonly distribute pollen from flower to flower as they go which leads to plants being pollinated and seeds to be produced.
This is a chemical change because there is a new substance that was created and the new chemical can cause other chemical reaction to happen compared to the 1st state of chemical that was in the cave. Because the cave water was exposed to another environment, the calcium bicarbonate, which is also known as salt. When the cave's groundwater was exposed to a different environment the atom in the cave water rearranged and crystallized.
Isotopes of same element has different number of neutrons with different masses and having same number of protons and electrons.
Radioactive isotopes are those isotopes which are radioactive in nature. The unstable nucleus results in the radioactivity process and this process will go on until the stable isotope (element) forms.
Thus, the nucleus of unstable isotopes of an element will decay leading to emission of radiation.
I dont know the answer choices but if isotopes is there then go with Isotopes