SECONDARY SCIENCE: CHEMISTRY Utah state curriculum: Standard 1 – Objective 3B. Students will understand that all matter in the universe has a common origin and is made of atoms, which have structure and can be systematically arranged on the periodic table. Correlate atomic structure and the physical and chemical properties of an element to the position of the element on the periodic table.

CHILDREN’S LITERATURE

HOW TO FIND THE NUMBER OF PROTONS, NEUTRONS, & ELECTRONS OF AN ELEMENT ON THE PERIODIC TABLE

Step 1 - Gather Information Step 1 - Gather Information. The first thing you will need to do is find some information about your element.

Step 2 - The Number of Protons. The atomic number is the same number of protons in an atom of an element. In our example, krypton's atomic number is 36.

Step 3 - The Number of Electrons Atoms must have equal numbers of protons and electrons. In our example, an atom of krypton must contain 36 electrons since it contains 36 protons.

Step 4 - The Number of Neutrons To find how many neutrons are in an element, first you need to find what’s called the mass number. - Mass Number = (Number of Protons) + (Number of Neutrons) OR the atomic weight rounded up to the nearest whole number. For krypton, it’s atomic weight is 83.80, rounded up is 84. the equation becomes: 84 = (Number of Protons) + (Number of Neutrons) *** hint. We know the # of protons because it’s the same as the atomic number. 84 = 36 + (Number of Neutrons) What number added to 36 makes 84? 48 is the number of neutrons in an atom of krypton.

ATOMIC WEIGHT ATOMIC NUMBER