Explanation

Calcium is crucial for:

• Building and maintaining strong bones and teeth
• Muscle function and contraction
• Nerve function and transmission
• Blood clotting and wound healing

Explanation

Amphoteric substances are those that can react with both acids and bases.

They can donate or accept protons (H+ ions), depending on the conditions.

Examples of amphoteric substances include water (H2O), amino acids, and certain metals like zinc and aluminum.

Explanation

• Red stars, also known as red dwarfs, typically have a surface temperature around 3000°C (5400°F).
• This is the coolest temperature range for stars, and it's what gives them their distinctive red color.

Explanation

A refracting telescope has two lenses:

1. A primary lens (objective) that collects and focuses light.
2. A secondary lens (eyepiece) that magnifies the focused light to form an image.

Explanation

• In a mercury thermometer, the mercury in the bulb expands and rises in the tube, which has a linear scale ranging from 94°F to 108°F.
• This specific range is commonly used for medical thermometers to measure human body temperature.

Explanation

• Atmospheric pressure is a scalar quantity that acts equally in all directions, pressing on surfaces from all sides.
• This is why a balloon expands in all directions when inflated, and why a submarine is squeezed from all sides by the surrounding water pressure.

Explanation

• Photosynthesis is the process by which plants, algae, and some bacteria.
• It convert light energy from the sun into chemical energy in the form of glucose (sugar), using carbon dioxide and water as reactants.

Explanation

• Magnesium (Mg) is an element, not a compound.
• It is a pure substance made up of only one type of atom.
• Whereas compounds are made up of two or more different elements.

Examples of compounds:

• Water (H2O) - Compound of Hydrogen and Oxygen
• Common salt (NaCl) - Compound of Sodium and Chlorine
• Washing soda (Na2CO3) - Compound of Sodium, Carbon, and Oxygen
• Carbon dioxide (CO2) - Compound of Carbon and Oxygen
  
• Sugar (C6H12O6) - Compound of Carbon, Hydrogen, and Oxygen

Explanation

The life cycle of a bee:

• Egg: Laid by the queen bee in the honeycomb cell.
• Larva (Grub): Hatches from the egg, fed royal jelly and pollen.
• Pupa (Cocoon): Transforms into a pupa, undergoing metamorphosis.
• Bee (Adult): Emerges from the pupa, ready to fly and perform colony tasks.

Explanation

• When the Moon and the Sun are on the same side of the Earth, we see a New Moon.
• This occurs when the Moon is between the Earth and the Sun, making the side of the Moon facing the Earth unilluminated.