Matter is anything that possesses mass, occupies space and may be perceived through one or more senses.
The physical divisions of matter are:
1. Solid : Solid matter is composed of tightly packed particles. A solid will retain its shape; the particles are not free to move around.
2. Liquid : Liquid matter is made of more loosely packed particles. It will take the shape of its container. Particles can...
In the air, there's nothing holding the body of the helicopter still - so the rotor blades spin one direction, but the torque applied to spin the rotors tries to spin the body of the helicopter in the opposite direction. The little rotor on the tail helps keep the body of the helicopter pointed in the same direction.
One major difference between Americans and Japanese is their cultural norms and values. For example, Americans tend to value individualism and independence, while Japanese tend to prioritize group harmony and collectivism. This can be seen in various aspects of daily life, such as communication style, decision-making processes, and social interactions. Additionally, the two cultures have different customs and traditions, including food, clothing, and holidays.
Sigma bond is stronger than Pi bond because of the following reasons:
- The extent of overlapping in Sigma bond is greater than in Pi bond.
- The electron density in intermolecular axis is more in Sigma bond than in Pi bond.
- There is free rotation of atom about Sigma bond but not about Pi bond.



Materials show varying behaviors based on their Poisson's ratio. High Poisson's ratio materials (near 0.5) contract significantly sideways when stretched and expand when compressed, seen in substances like rubber. Low Poisson's ratio materials (near 0) undergo minimal width change during axial deformation, typical of metals and common engineering materials.