Explanation

• The shielding effect decreases across a period.
• This is because the increasing nuclear charge is not fully counterbalanced by the same number of inner electrons, resulting in a weaker shielding effect.

Explanation

The number of bioelements considered vital for life is 16. These essential elements include:

1. Carbon (C)
2. Hydrogen (H)
3. Oxygen (O)
4. Nitrogen (N)
5. Phosphorus (P)
6. Sulfur (S)
7. Potassium (K)
8. Calcium (Ca)
9. Magnesium (Mg)
10. Iron (Fe)
11. Sodium (Na)
12. Chlorine (Cl)
13. Copper (Cu)
14. Zinc (Zn)
15. Manganese (Mn)
16. Iodine (I)

Explanation

• A group of similar cells that perform a specific function combine to form tissue.
• Tissues then combine to form organs.
• Organs work together to form systems.

Explanation

• The shortest distance between two points is called displacement.
• Displacement is a measure of the straight-line distance between two points.
•  It is a scalar quantity.

Key Point: The longest distance between two points is called the circumference (if the points are on a circle) or a diagonal (if the points are on a polygon or a rectangle).

Explanation

• Volvox is a genus of green algae that includes about 20 species of aquatic, photosynthetic organisms.
• They are characterized by their spherical or ellipsoidal shape and are typically found in freshwater environments.
• Volvox species are known for their unique colony structure, which consists of a hollow sphere of cells surrounding a central cavity.