When excess carbon (IV) oxide is passed into lime water; the turbidity produced initially disappears due to the formation of

When excess carbon (IV) oxide is passed into lime water; the turbidity produced initially disappears due to the formation of

  1. calcium oxide
  2. calcium carbide
  3. calcium hydrogentrioxocarbonate (IV) ✓
  4. trioxocarbonate (IV) acid

Explanation

Pathogens spread via: airborne (droplets – flu, TB), waterborne (contaminated water – cholera, typhoid), direct contact (skin, bodily fluids – HIV, ringworm), vectors (mosquitoes – malaria; tsetse fly – sleeping sickness).

Breaking transmission chains: vaccination (immunity), sanitation (clean water, waste disposal), hygiene (handwashing), vector control (mosquito nets, insecticides), quarantine (isolating infected).

Body defenses: skin barrier, mucus traps pathogens, white blood cells attack invaders, antibodies neutralize specific pathogens. Immune memory enables faster response to repeat infections.