Everything from the 3 lessons of this topic on a few pages: the key idea of each lesson, the diagram to remember, the points to learn and the traps examiners set. Read it, cover it, test yourself.
Diffusion is the net movement of particles from a region of their higher concentration to a region of their lower concentration, down a concentration gradient, as a result of their random movement. The energy comes from the kinetic energy of the moving molecules and ions themselves, so the cell spends no energy. Some substances, such as oxygen, carbon dioxide and glucose, move into and out of cells by diffusion through the cell membrane.
Do not say particles stop moving when diffusion is complete. They keep moving at random; it is the net movement that becomes zero because there is no longer a concentration gradient.
"Higher concentration" on its own is not a factor. The rate depends on the difference in concentration between the two regions, the concentration gradient.
Water diffuses through partially permeable membranes by osmosis, and moves into and out of cells this way through the cell membrane. Extended: osmosis is the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane. Plants are supported by the pressure of water inside their cells pressing outwards on the cell wall.
In osmosis it is the water that moves, not the solute. The sucrose molecules are too large to pass through the membrane. Never write that "sucrose moves out by osmosis".
"No change in mass" does not mean no water moved. Water still crosses both ways at the same rate; there is no net movement because the solution matches the concentration of the cell sap.
Plant cells do not burst in pure water: the cell wall resists the turgor pressure. Only cells without a wall, such as red blood cells, burst. A plasmolysed cell has lost so much water that its membrane has pulled away from the wall; a flaccid cell has only lost its turgor.
Active transport is the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (against a concentration gradient), using energy from respiration. Extended: protein carriers in the membrane move the molecules or ions across, which lets cells such as root hair cells take up mineral ions from very dilute soil water.
Active transport needs energy from respiration. Do not say the energy comes from the kinetic energy of particles (that is diffusion), and do not say active transport "makes" energy: it uses it.
Root hair cells take up water by osmosis but mineral ions by active transport. Keep the two processes separate in your answers.