Identify the number of core and valence electrons for each atom. Xe : core electrons Xe : valence electrons Ca : core electrons Ca : valence electrons Br : core electrons Br : valence electrons

Xe : core electrons = 46

Xe : valence electrons = 8

Ca : core electrons = 18

Ca : valence electrons = 2

Br : core electrons = 28

Br : valence electrons = 7

Explanation:

Xe atom has atomic number 54, as a group 8 element, it has a valence (outermost) electrons of 7 meaning the rest of 46 electrons are core (inner) electrons. Ca atom is in group 2 in the periodic table. Having 20 electrons, two electrons are on the valence shell while the rest 18 are cor electrons. bromine is a halogene (group 7) and hence 7 valence electrons. it has 35 electrons. it has 28 core electrons.