elements r through s

radium (Ra), a.n. 88radon (Rd), a.n. 86rhenium (Re), a.n. 75rhodium (Rh), a.n. 45rubidium (Rb), a.n. 37ruthenium (Ru), a.n. 44rutherfordium (Rf), a.n. 104samarium (Sm), a.n. 62scandium (Sc), a.n. 21seaborgium (Sb), a.n. 106selenium (Se), a.n. 34silicon (Si), a.n. 14silver (Ag), a.n. 47sodium (Na), a.n. 11strontium (Sr), a.n. 38sulfur (S), a.n. 16