Explanation

Near Earth's surface, the acceleration due to gravity (g) is approximately 10 meters per second squared (10 ms^-2).

This is a fundamental constant that describes the strength of gravity on our planet.

Explanation

• Fluorine (F) has an atomic number of 9 and an electronic configuration of 1s² 2s² 2p⁵.
• To achieve a stable electronic configuration, two fluorine atoms share one electron each to form a covalent bond.
• Resulting in a configuration similar to that of neon (Ne), which is 1s² 2s² 2p⁶.

Explanation

• A hydrogen bond is a type of intermolecular force that arises between a highly electronegative atom (such as oxygen, nitrogen, or fluorine).
• A hydrogen atom that is bonded to a highly electronegative atom.
• This interaction is typically weak compared to covalent bonds.
• But it is strong enough to influence the physical and chemical properties of molecules.

Explanation

• As you move down a group in the periodic table, the atomic size increases.
• This means that the outermost electrons are farther away from the nucleus, making it easier for the atom to gain an extra electron.
• As a result, the electron affinity decreases down a group.

Explanation

• In 1869, Dmitri Mendeleev proposed his periodic law, which states: "When the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically."
• This law allowed him to create the first periodic table, where elements were arranged in a logical order based on their atomic masses and chemical properties.

Explanation

Root hairs are thin, hair-like structures that extend from the roots of plants, increasing the surface area for absorption of water and nutrients from the soil. They play a crucial role in:

• Absorbing water and minerals
• Anchoring the plant in the soil
• Facilitating the uptake of nutrients

Explanation

• A non-metal atom forms an anion (a negatively charged ion) by gaining one or more electrons.
• This means that the atom acquires additional electrons to form a negative ion.

Explanation

Each gram of fat supplies the body with approximately 9 calories.

This is more than the energy provided by carbohydrates (4 calories per gram) and protein (4 calories per gram).

Explanation

Iron deficiency is associated with decreased cognitive abilities and resistance to diseases.

Iron plays a crucial role in the immune system, and deficiency can impair the body's ability to fight off infections.

Explanation

Facilitated diffusion is a type of passive transport that uses carrier proteins to move specific substances across the cell membrane without energy input.

This process allows cells to regulate the movement of essential molecules, like sugars and amino acids, into or out of the cell.