science

• word equation: water + carbon dioxide through the sunlight = glucose + oxygen
• what captures the sunlight and how is it help during photosynthesis?

  Chlorophyll captures sunlight. It will convert the light energy to chemical energy
• Why the plants didn't use all the glucose immediately?

  to form starch, it is a carbohydrate form by many glucose molecules.
• Why need to put leaf in the BOILING water?

  to break down the cell membranes and stop all the chemical reactions in the leaf cells
• why need to put leaf into the ethanol?

  to remove the chlorophyll so when putting iodine solution the colour will be visible.
• How to identify if there's oxygen in the test tube?

  use a glowing splint, if it relights then it is oxygen.
• how water provides support to the plant?

  water creates turgor pressure which let the vacuole swells and push against the cell wall
• what will happen if the plant does not have water?

  the vacuole will shrink and the plant cell will become flaccid and wilt
• what is organic fertilisers?

  made out of living things, release mineral salts to the soil
• what is inorganic fertilisers?

  made out of man made fertilisers produced from chemical
• what is the function of nitrate?

  leaf development, growth and repair, prevent defiency which can lead the leaf turn yellow
• what is the function of phosphorus?

  development of roots, flowers, seeds and fruit
• what is the function of potassium?

  development of roots, to help plants resist against disease and promote flower and fruit
• how do plants obtain glucose and oxygen?

  through sunlight, convert carbon dioxide to glucose and water to oxygen.
• what is hydroponics?

  plant roots immersed in solutions which are rich in mineral salts
• what is aeroponics?

  plant roots are exposed to the air and will sprayed with solutions
• advantages of hydroponics and aeroponics

  hydroponics - no need soil

  - require less labor

  aeroponics - faster growth

  - healthier
• what did Dalton's model state?

  the atom is a very small, hard sphere that it is indivisible.
• what did Thomson's model state?

  The atom is a continuous mass of positive charge contain negative charged electrons.
• what did Rutherford's model state?

  atom is mostly empty space, center contains positive nucleus surround negative electrons
• what does bohr's model state?

  atom has a positive charged nucleus, electrons moved in fix orbits around the nucleus