Starter quiz
- Match the following terms to the correct definition.
- atomic mass⇔Relative mass of an atom, the total mass of its protons and neutrons. ✓
- atomic number⇔Number of protons in the nucleus of an atom of an element. ✓
- atom⇔The smallest particle of an element that can exist. ✓
- molecule⇔A group of atoms chemically bonded together. ✓
- Which of the following are elements?
- O₂ ✓
- NH₃
- CO
- Co ✓
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- Oxygen has an atomic mass of 16 and an atomic number of 8. How many electrons does an atom of oxygen have?
- '8' ✓
- Lithium is in Group 1, period 2 of the periodic table. It has an atomic number of 3. How many electrons are found in the outer shell of a lithium atom?
- 1 ✓
- 2
- 3
- 8
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- Which of the following are examples of diatomic molecules?
- O₂ ✓
- N₂ ✓
- CO₂
- CuCO₃
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- Which of the following statements about subatomic particles are correct?
- Electrons have a relative charge of +1.
- Neutrons have no charge. ✓
- Protons and electrons are found in the nucleus of atoms.
- Protons have a relative mass of 1. ✓
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Exit quiz
- Match the following terms to the correct definitions.
- electron configuration⇔The arrangement of electrons in shells, in an atom or ion. ✓
- outer shell⇔The highest energy level in an atom, contains electrons. ✓
- cation⇔A particle with a positive charge. ✓
- anion⇔A particle with a negative charge. ✓
- In which of the following are electrons donated and accepted?
- giant covalent substances
- simple covalent substances
- ionic substances ✓
- metallic substances
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- Which of the following are monoatomic substances?
- krypton, Kr ✓
- oxygen, O₂
- carbon dioxide, CO₂
- nitrogen, N₂
- helium, He ✓
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- What type of bonding forms between non-metal atoms?
- 'covalent' ✓
- Why is an oxygen atom considered to be unstable?
- It does not have a full outer shell of electrons. ✓
- The outer shell contains eight electrons.
- The outer shell contains six electrons. ✓
- It has a full outer shell of electrons.
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- Which of the following diagrams shows an ionic substance?
Worksheet
Presentation
Video
Lesson Details
Key learning points
- There are five different types of substance: monatomic, simple covalent (molecules), giant covalent, ionic and metallic
- The outer shell in most atoms can hold 8 electrons but, in hydrogen and helium, it can only hold 2 electrons.
- Most atoms increase their stability by forming bonds with other atoms so that they have a full outer shell of electrons.
- Some atoms will share electrons with other atoms to increase their stability.
- Some atoms will lose or gain electrons to increase stability forming cations or anions, respectfully.
Common misconception
Atoms react because they 'want' to gain a fuller outer shell of electrons – atoms don't have feelings. Monatomic means one atom and may be confused with the term element, which means one type of atom.
Take care with language and avoid personifying the atoms. Make sure that definitions and terms are used correctly.
Keywords
Molecule - A molecule is a particle consisting of a fixed number of (two or more) non-metal atoms covalently bonded together.
Noble gas configuration - When an atom has a full outer shell of electrons, it has a noble gas electron configuration.
Outer shell - The outer shell is the highest energy level in an atom and is usually the furthest from the nucleus.
Cation - a particle with a positive charge.
Anion - a particle with a negative charge.