A certain element X has 3 isotopes. Their masses and abundances are as follows X-25 has an abundance of 57.43%. X-26 has an abundance of
22.37%. X-28 has an abundance of 20.20%. What is the atomic mass of X?
Round your answer to the nearest hundredth.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom

Heat of fusion= heat/mass  heat of fusion = 12.03kj/36 g= 0.3342 kj/g or 334.2 j/g

Polyethylene is a strong synthetic polymer that can be used to make toys and bottles. polyethylene is a plastic material called thermoplastic. one very useful property of thermoplastic is that when it is heated it turns into liquid, which can be molded into desired shape and size. also the material do not dissolve at room temperature.