What symbol for every chemical element that has atomic number less than 15 and atomic mass greater than 23.5 u .

Magnesium and Aluminum Mg & Al Explanation:Magnesium’s atomic mass is 24.31 and Aluminum’s atomic mass is 26.98.

Atomic m. Element Atomic no. Symbol 1.0079u Hydrogen 1 H 4.0026u Helium 2 He 6.941u Lithium 3 Li Additional information:- ★ Atomic number : The number of protons in one atom of an element is known as atomic number. Atomic number of an element = No. of protons in one atom of element.The atomic no. of element is denoted by the letter z .

1.  Lutetium                  Atomic Number  =  71                  Atomic Mass      =  174.97 u 2.  Hafnium                  Atomic Number  =  72                  Atomic Mass      =  178.49 u 3.  Tantalum                  Atomic Number  =  73                  Atomic Mass      =  180.95 u 4.  Tungsten                  Atomic Number  =  74                  Atomic Mass      =  183.85 u

Those Al. Si. P. i think

You should be able to locate them on the periodic table as long as you know which part the atomic number is and which part the atomic mass is.

Leave a Comment