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Atomic Structure and Chemical Bonding

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

What is inside an atom, and how do protons, neutrons and electrons define an element and its isotopes?

Describe the structure of the atom in terms of protons, neutrons and electrons, define proton number and nucleon number, explain isotopes, and write the electronic configuration of the first twenty elements
A focused answer to the O-Level Chemistry outcome on atomic structure. Protons, neutrons and electrons, proton and nucleon number, isotopes and why they behave alike chemically, and electronic configuration of the first twenty elements.
8 min answer →

How do non-metal atoms bond by sharing electrons, and why do simple molecular and giant covalent substances differ so much?

Describe covalent bonding as the sharing of electron pairs, draw dot-and-cross diagrams for simple molecules, and contrast the properties of simple molecular substances with giant covalent structures
A focused answer to the O-Level Chemistry outcome on covalent bonding. Sharing electron pairs to reach full shells, dot-and-cross diagrams for simple molecules, and why simple molecular substances melt easily while giant covalent structures do not.
9 min answer →

How do metals and non-metals bond by transferring electrons, and why do the compounds they form have such high melting points?

Describe ionic bonding as the transfer of electrons to form ions with noble-gas configurations, draw dot-and-cross diagrams, and relate the giant ionic lattice to the properties of ionic compounds
A focused answer to the O-Level Chemistry outcome on ionic bonding. Electron transfer to form ions with noble-gas configurations, dot-and-cross diagrams, the giant ionic lattice, and how it explains high melting points and conduction when molten.
9 min answer →

How does metallic bonding explain why metals conduct, bend and stay solid at high temperatures, and why alloys are harder than pure metals?

Describe metallic bonding as a lattice of positive ions in a sea of delocalised electrons, relate it to the properties of metals, and explain why alloys are harder than pure metals
A focused answer to the O-Level Chemistry outcome on metallic bonding. The lattice of positive ions in a sea of delocalised electrons, how it explains conduction, malleability and high melting points, and why alloys are harder than pure metals.
8 min answer →