In your own words, define an intrinsic material, a negative temperature coefficient, and covalent bonding.

Understanding the concept of a negative temperature coefficient (NTC) is crucial in the realm of electronics and material science. Essentially, materials with an NTC property have a peculiar behavior: as their temperature increases, their electrical resistance decreases. This is an important characteristic for various applications, such as in temperature sensors or thermistors.

For example, in a thermistor, the NTC allows it to act as a temperature-dependent resistor. This means that it can be used in circuits to measure or respond to temperature changes. In contrast to metals which typically have a positive temperature coefficient, NTC materials can offer more sensitivity in temperature detection for a range of technologies. Also, understanding the effects of temperature on resistance assists in choosing the right materials for building electronic devices that need to function accurately across diverse temperatures.

Covalent bonding is fundamental in forming the molecules all around and within us. When discussing covalent bonds, we dive into how atoms with similar electronegativities come together to share pairs of electrons in their outer shells, seeking stability. This mutual sharing is the force that holds the atoms together in a strong fashion.

Formation of molecules

Through this sharing, atoms achieve a full valence shell and reach a more stable, energetically favorable state, often resembling the electronic configuration of noble gases. This is evident in water (H2O), oxygen (O2), or carbon dioxide (CO2), where atoms are bound in a tight embrace by shared electrons. In materials science, covalent bonding is significant in the structure and properties of semiconductors such as silicon and germanium, which form the backbone of electronic components.

Semiconductors are like the superheroes of material science, bridging the gap between the conducting world of metals and the insulating realm of non-metals. Their abilities stem from their unique atomic arrangement and the covalent bonds that link their atoms together. At room temperature, semiconductors have a lower electrical conductivity than metals but are still able to conduct electricity. This is what sets them apart as the foundation of modern electronics.

For intrinsic semiconductors, such as pure silicon or germanium, their conductive behavior is solely due to the movement of electrons and holes in their crystal lattice—without any external doping. As temperature rises, more electrons gain enough energy to jump into the conduction band resulting in better conductivity. Understanding how temperature affects the intrinsic properties of these materials is key to leveraging their functions in devices such as diodes, transistors, and integrated circuits.

Electrical resistance is a fundamental concept that explains how materials oppose the flow of electric current. Just like water flows more freely through a wide pipe than a narrow one, electric current passes more easily through materials with low resistance than those with high resistance.

Factors influencing resistance

Several factors determine the resistance in a material, including its temperature, which we've seen has a remarkable effect in materials with a negative temperature coefficient. Another factor is the nature of the material itself—its atomic structure and how tightly bound the electrons are. Metals, with their 'sea of electrons,' generally face less resistance to current flow than insulating materials, whose electrons are more tightly bound within the covalent bonds. Recognizing these differences helps in designing circuits and selecting materials for specific electronic applications where resistance plays a critical role in functionality and efficiency.