Why is fluorine, chlorine, bromine, and iodine grouped together?

Agas is contained in a thick walled balloon when the pressure changes from 1.21 atm to 2.52 the volume changes from 3.75 l to 1.72 l and the temperature change from 293k to blank k

Using data from seismic waves, geologists have learned that earth’s interior is made up of several

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true