The temperature at which half of the dna helical structure is lost is called the:

Hi the answer is called the Tm.
Hope this helps.

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass

Sorry  i don't understand can you rephrase that