Explanation

Glass is amorphous.

It lacks a definite crystalline structure.

It behaves like a supercooled liquid, flowing extremely slowly over time.

Explanation

Roentgen rays are another name for X-rays.

It was discovered by Wilhelm Conrad Röntgen in 1895.

They are electromagnetic waves with high energy and short wavelengths.

It is used in medical imaging and other applications.

Explanation

The p-orbital has a dumb bell shape (two lobes on opposite sides of the nucleus).

It is oriented along one axis (e.g., px, py, pz) and has a nodal plane at the nucleus.

Explanation

Polonium (Po) is a radioactive element discovered by Marie Curie.

It has no stable isotopes and emits alpha particles.

Explanation

The unit cell is the smallest repeating unit in a crystal lattice that fully represents the entire crystal's symmetry and structure when extended in three dimensions.

It is repeated periodically along the three axes (length, width, height) to form the complete crystal lattice.

It defines the crystal's geometry, including atomic positions, angles, and edge lengths (lattice parameters).

Explanation

The Celsius to Kelvin conversion is given by:

$$K=°C+273$$

So, $0\mathrm{°}C=0+273=273K$.

Explanation

Convection is the transfer of heat through the movement of a fluid, and only liquids and gases can flow freely, allowing for the movement of heat currents. 

Additional information:

Solids and gases:

While solids can transfer heat through conduction, they cannot convect because their particles are fixed in place and cannot move freely. 

Liquids and solids:

Convection only occurs in liquids and gases. Solids do not convect due to their fixed particle structure. 

All states of matter:

Convection is specifically related to the movement of fluids, which excludes solids. 

Explanation

1. The chemical formula for water is H₂O.

2. Atomic masses:

   • Hydrogen (H) = 1 amu each → 2 × 1 = 2 amu

   • Oxygen (O) = 16 amu

3. Total molecular mass = 2 (from H) + 16 (from O) = 18 amu.

Explanation

Graham's Law of Diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass.

$$\text{<font color="\#0000ff"><b>Rate</b></font>}<font\; color="\#0000ff"><b>\propto </b></font>\frac{\mathrm{<font\; color="\#0000ff"><b>1</b></font>}}{\sqrt{\mathrm{<font\; color="\#0000ff"><b>M</b></font>}}}$$

Compare molar masses:

CH₄ (Methane): 16 g/mol

N₂ (Nitrogen): 28 g/mol

O₂ (Oxygen): 32 g/mol

H₂ (Hydrogen): 2 g/mol (lightest)

Since H₂ has the smallest molar mass, it diffuses the most rapidly.

Explanation

Hydrochloric acid (HCl) is a strong acid that completely dissociates in water, releasing H⁺ ions.

The pH scale ranges from 0 to 14, where pH < 7 indicates acidity.

Since HCl increases H⁺ concentration, its pH is always less than 7.