A hypothetical pure element consists entirely of two isotopes. The natural percent abundance of the isotope with mass 25.2\,\mathrm is 81.1\%. The other isotope has mass 29.8\,\mathrm. Calculate the atomic weight of the naturally occurring element.

The image shows a process that releases nuclear energy which statement best identifies the process shown the process must be fusion because energy is released the process must be fusion because of have your nucleus formed a smaller nuclei the process must be fission because a large nucleus breaks into smaller nuclei the process must be fission because neutrons are formed

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?