Which of these is always present in the atmosphere?

Which element has the lowest electronegativity? calcium(ca) gallium(ga) selenium(se) bromine(br)

What type(s) of intermolecular forces are expected between ch3ch2cooh molecules? dipole forces, induced dipole forces, hydrogen bonding

Choose all the answers that apply. fluorine (f) has an atomic number of 9 and an atomic weight of 18.99. fluorine has a. 9 protons b. 10 neutrons c. 18 electrons d. an atomic mass of 19 e. at least one isotope