Atomic structure and the periodic table- basics

Question	Answer
Describe the structure of an atom:	The nucleus contains the protons and neutrons. The electrons then move around the nucleus in electron shells.
What charge does an atom have?	They are neutral; they have no charge overall.
Describe the properties of Subatomic particles:	Image: Subatomic Particles (binary/octet-stream)
How are ions different to atoms?	In an ion, the number of protons doesn't equal the number of electrons. This means it has an overall charge.
What is an element?	An element is a substance that is made of only one sort of atom. The substance has to also contain atoms with the same number of protons.
What are isotopes?	Isotopes are different forms of the same element, which have the same number of protons but a different number of neutrons. They have the same atomic number but different mass numbers.
What is the relative atomic mass?	An average mass, taking into account the different masses and abundances of all isotopes making elements.
Give the equation for relative atomic mass:	(% of isotope 1 × mass of isotope 1) + (% of isotope 2 × mass of isotope 2) ÷ 100 So in the case of chlorine: (75 × 35) + (25 × 37)∕100 = 2625 + 925∕100 = 35.3

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	Created by Clare Noone over 6 years ago