Nguyên tử X có tổng số hạt proton, nơtron ở hạt nhân là 27. Trong nguyên tử X tỉ lệ số hạt mang điện so với không mang điện là 13/7 . Xác định tên nguyên tố và viết ký hiệu nguyên tử đầy đủ của X.

How many moles of gas are present if p=11 atm, v=12l, t=185k?

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.

The small bags of silica gel you often see in a new shoe box are placed there to control humidity. despite its name, silica gel is a solid. it is a chemically inert, highly porous, amorphous form of sio2. because water vapor readily adsorbs onto the surface of silica gel, it acts as a desiccant. despite not knowing mechanistic details of the adsorption of water onto silica gel, from the information provided you should be able to make an educated guess about the thermodynamic characteristics of the process. predict the signs for δg, δh, and δs for the adsorption of water.