How many protons electrons and neutrons are in

How many protons, electrons, and neutrons are in an atom? http: //physicsed. buffalostate. edu/Wiley/CJ 6 e/img 30/PTE. gif

Step 1 n Use your periodic table to find an element http: //education. jlab. org/qa/pen_number. html

Step 2 n The number of Protons (+ charge) n The atomic number = # protons n Kr has 36 protons http: //education. jlab. org/qa/pen_number. html

Step 3 n n n The number of Electrons (- charge) Remember atoms have no overall charge. Atoms must have an equal # of protons and electrons #protons=#electrons Kr has 36 electrons

Step 4 n The number of Neutrons (no charge) Mass # (atomic weight rounded to nearest whole #) n Neutrons = Mass # - Protons n n n Neutrons = 84 – 36 Neutrons = 48

Summary n n n Number of Protons = Atomic # Number of Electrons = Protons Number of Neutrons = Mass # - Protons

Problems 1. Find the protons (p+), electrons (e-), neutrons (n) of Oxygen 2. Find the p+, e-, n of Xenon (Xe) 3. Find the p+, e-, n of Zirconium (Zr)

Oxygen (O) p+, e-, n n n n Number of Protons = Atomic # Number of Electrons = Protons Number of Neutrons = Mass # - Protons = 8 Electrons = 8 Neutrons = 16 -8 = 8

Xenon (Xe) p+, e-, n n n n Number of Protons = Atomic # Number of Electrons = Protons Number of Neutrons = Mass # - Protons = 54 Electrons = 54 Neutrons = 131 -54 = 77

Zirconium (Zr) p+, e-, n n n n Number of Protons = Atomic # Number of Electrons = Protons Number of Neutrons = Mass # - Protons = 40 Electrons = 40 Neutrons = 91 -40 = 51