Friction. It transforms other forms of energy into thermal energy
Physical change because it's only changing the shape of the gold.
Other natural material such as clay, wood, and stones can be changed into art.
Clay is pliable and is very easy to be molded into different shapes and sizes.
Wood can easily carved into different shapes, also different patterns can be easily etched on wood.
Stones of different variety and from different geological sources are painstakingly converted into statues or portraits of different life forms and scenery.
Answer:
The given statement - The main criterion for sigma bond formation is that the two bonded atoms have valence orbitals with lobes that point directly at each other along the line between the two nuclei , is <u>True.</u>
Explanation:
The above statement is correct , because the sigma bond is produced by the head on overlapping, the orbitals should all point in the same direction.
<u>SIGMA BONDS -</u> Sigma bonds (bonds) are the strongest type of covalent chemical bond in chemistry. They're made up of atomic orbitals that collide head-on. For diatomic molecules, sigma bonding is best characterized using the language and tools of symmetry groups.
Head-on overlapping of atomic orbitals produces sigma bonds. The concept of sigma bonding is expanded to include bonding interactions where a single lobe of one orbital overlaps with a single lobe of another. Propane, for example, is made up of ten sigma bonds, one for each of the two CC bonds and one for each of the eight CH bonds.
Hence , the answer is true .
