Explanation

A liquid crystal is a state of matter that exhibits properties of both liquids and crystals.

It requires the molecules to have a specific structure, often long and rigid, to form ordered phases.

While soap can form structures similar to liquid crystals when mixed with water (forming micelles), pure soap is not a liquid crystal.

The other options listed, DNA, cholesteryl format, and engine oil, can all exhibit liquid crystal properties under certain conditions. 

Explanation

Beta particles are high-energy electrons or positrons that interact frequently with air molecules.

These collisions cause them to change direction randomly, resulting in a zigzag or erratic path. 

Explanation

The smallest unit that can evolve is a population. 

Evolution refers to changes in the allele frequencies within a population over time

Since individual organisms cannot evolve on their own,

it's the group of individuals (the population) that experiences these changes. 

Explanation

Phenology examines the timing of recurring natural events, such as the flowering of a plant, the arrival of a migrant bird, or the emergence of a caterpillar, with seasonal climatic changes. 

Explanation

Radio telemetry is commonly used to track amphibians

But can only be used on relatively large individuals.

Harmonic direction finding can be used to track smaller animals, but its effectiveness has not been fully evaluated.

Explanation

 It hibernates throughout the winter in the northwestern Himalayas

Currently, it only exists in Asia, mainly confined in the Himalayas of India, Bhutan, Nepal, China, and Pakistan.

Explanation

When a gas expands suddenly (an adiabatic expansion), it does work on the surroundings without any heat exchange.

As a result, the internal energy of the gas decreases, leading to a decrease in temperature.

Explanation

PbCl₂ (lead(II) chloride) is ionic.

Lead(II) chloride forms an ionic lattice structure with chloride ions,

while PbCl₄ is a covalent complex.

Explanation

In female mosquitoes, this mouth part pierces the skin of a person or animal and sucks out blood.

The male's proboscis is not strong enough to pierce the skin, and males do not feed on blood.

Both female and male mosquitoes use the proboscis to feed on flower nectar and fruit juices

Explanation

• the transfer of heat when waves or rays are dispersed from an object called Radiation
• ***
• different methods of heat transfer
• Conduction is heat transfer through stationary matter by physical contact. 
• Convection is the heat transfer by the macroscopic movement of a fluid.
• Heat transfer by radiation occurs when microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed.