- Compound: two or more different elements combined together chemically
- Octet Rule: when bonding occurs, atoms tend to reach an electron arrangement with 8 electrons in the outermost energy level
- Ion: a charged atom or group of atoms
- Ionic bonding: the force of attraction between oppositely charged ions in a compound. Formed by the complete transfer of an electron from one atom to another
- molecule: a group of atoms joined together, the smallest particle of an element with can exist independently
- valency: the number of atoms of hydrogen (or any monovalent element) with which each atom of the element combines
- Transition... (More)
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I am not sure about the exact percentages but its definitely biology. And for biology, you can get asked a definition in any part of the exam.
From looking at the past papers about 90% of the marks for Biology can be gained from knowledge of all the definitions and theory. Most questions are not direct definitions but theory questions like "describe the..." and "draw the...". Direct definitions are about 20% of the paper. As the paper is mostly theory based, calculations are quite rare unlike chemistry and physics.
For chemistry on the other hand the marks are more mixed up. I would say about 55 - 60% can be gained from definitions and theory while the rest come from calculations. The first few lab experiment and... (More)
– As you move to the right across a period of elements, electronegativity increases.
– As you move down a group, electronegativity decreases.
– As you move down a group, atomic radius increases.
– As you move across a period, atomic radius decreases.
First Ionization Energy:
– As you move down a group, first ionization energy decreases.
– As you move across a period, first ionization energy increases.