Explanation

Methane is the simplest of saturated hydrocarbons with a chemical formula CH4.

It consists of four hydrogen atoms and one carbon atom.

It is the simplest alkane.

Explanation

Power is calculated as the rate of work done or energy transferred:

Power = Work / Time

= 20 J / 10 s

= 2 W

So, the machine's power output is 2 watts.

Explanation

• Light travels in a straight line.
• It is also known as a rectilinear path.
• It in a homogeneous medium like air or vacuum.

Explanation

• Omnivores are animals that eat both plants and animals.
• They have adaptations that allow them to digest and extract nutrients from a wide variety of food sources, including fruits, leaves, insects, small animals, and even carrion.
• Examples of omnivores include humans, bears, pigs, chimpanzees, and raccoons.
• Only plants: Herbivores (e.g., cows).
• Only animals: Carnivores (e.g., lions).

Explanation

In the modern periodic table, there are 7 periods (horizontal rows) and 18 groups (vertical columns).

Explanation

• When blue litmus paper is dipped in an acid, it turns red.
• This is because the acid changes the color of the litmus paper from blue to red.

Note: When red litmus paper is dipped in a base, it turns blue.

Explanation

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

1 kilocalorie (kcal) = 4184 joules, commonly used in food energy.

1 calorie (cal) = 4.184 joules, so 1000 cal = 4184 J.

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)