sand is a solid but most people think it is not sand comes from the ocean and contains some elements in it technically, sand has a definite shape as a grain.
About this type of question: My answer is that beryllium is small in size. So, the charge density (charge/radius) is extremely high. So, the force of attraction between the electrons in orbitals and proton in nucleus is very strong. When beryllium is encountered with the other elements (i.e. chlorine), the electrons cannot loss to environment(due to strong force of attraction), but the beryllium will be polarised to become positively charge and hence attract the electron from other elements to form the covalent compound (BeCl2 which is Cl-Be-Cl). So the beryllium hydride is a polar covalently bonded compound.
sand is a solid but most people think it is not sand comes from the ocean and contains some elements in it technically, sand has a definite shape as a grain.
Some plastics are, some are not. Polymers like polyethylene and polypropylene can be partially crystalline. Typical commercial polystyrene is not crystalline, although a crystallized resin form (syndiotactic polystyrene) has been produced that resists deformation up to about 270 degrees C.
About this type of question: My answer is that beryllium is small in size. So, the charge density (charge/radius) is extremely high. So, the force of attraction between the electrons in orbitals and proton in nucleus is very strong. When beryllium is encountered with the other elements (i.e. chlorine), the electrons cannot loss to environment(due to strong force of attraction), but the beryllium will be polarised to become positively charge and hence attract the electron from other elements to form the covalent compound (BeCl2 which is Cl-Be-Cl). So the beryllium hydride is a polar covalently bonded compound.