Explanation

Cracks on roads can occur due to expansion, contraction, and changes in temperature.

Expansion occurs when materials heat up and expand, while contraction happens when they cool down and shrink.

These changes in temperature can cause stress on the road surface, leading to cracks.

Explanation

Alkali metals (such as lithium, sodium, potassium, etc.) act as reducing agents.

They readily lose their single valence electron to form positive ions, which means they donate electrons in reactions

Explanation

Sodium hypochlorite (NaClO), usually as a 3–6% solution in water

It is usually called "liquid bleach" or just "bleach"

Sodium hypochlorite acts as a powerful disinfectant and stain remover, making it effective for various cleaning and sanitizing purposes.

Explanation

The dissolving of salt in water is a physical change because:

Reversible Process: The salt can be recovered by evaporating the water (no new substance is formed).

Molecular Level: Salt (NaCl) dissociates into ions (Na⁺ and Cl⁻) but retains its chemical identity.

Explanation

Helium is used in weather balloons.

Because it is lighter than air and non-flammable.

Explanation

Compressed natural gas (CNG) has the same chemical composition as methane, which is the primary component of Sui gas: 

Chemical formula

The chemical formula for CNG is CH4, which is also the chemical formula for methane. 

Composition

Sui gas is made up of 60–90% methane, 0–20% ethane, 0–20% propane, and 0–20% butane

Explanation

While creep is a slow and gradual process, it's still not recommended to try to outrun any mass wasting phenomenon.

Creep can still be unpredictable and may accelerate suddenly, making it dangerous to be in the area.

Explanation

Borazine, also known as borazole, has the chemical formula B₃H₆N₃.

It is a compound that resembles benzene in structure but with alternating boron and nitrogen atoms in the ring, along with hydrogen atoms. 

Explanation

Osmium is the densest naturally occurring element, with a density of approximately 22.59 g/cm³.

This makes it the highest density transition element, far exceeding the densities of elements like mercury and zinc.

Explanation