In your own words, explain the difference between a physical and chemical change. Also providing an example of each.(3 points)
A physical change refers to a transformation of a substance that does not change its chemical composition or identity. In other words, it is a change in the physical properties of a substance, such as its shape, size, or state of matter, without altering its chemical structure. An example of a physical change is the melting of ice. When ice melts, it changes from a solid to a liquid state, but it still remains water.
On the other hand, a chemical change involves the breaking and forming of chemical bonds, resulting in the creation of new substances with different chemical properties. It is a change in the chemical composition and identity of a substance. A classic example of a chemical change is the burning of wood. When wood is burned, it undergoes a chemical reaction known as combustion, which releases heat and produces ash, smoke, and carbon dioxide. The original wood substance has transformed into new compounds during the process of burning.
what is the correct answer
The correct answer provided above explains the difference between physical and chemical changes accurately. It mentions that a physical change does not alter the chemical composition or identity of a substance, while a chemical change involves the creation of new substances with different chemical properties. Additionally, examples of each have been provided to further illustrate the concept.
In your own words, explain the difference between ionic and covalent bonds. Also providing an example of each. (3 points)
Ionic and covalent bonds are two different types of chemical bonds that form between atoms.
1. Ionic Bond: An ionic bond is formed when atoms transfer electrons from one atom to another. This occurs between a metal and a non-metal. In an ionic bond, one atom loses electrons to become positively charged (cation), while the other atom gains those electrons to become negatively charged (anion). The attraction between the opposite charges holds the ions together. An example of an ionic bond is the formation of table salt (sodium chloride). Sodium (Na) transfers one electron to chlorine (Cl), forming Na+ cations and Cl- anions.
2. Covalent Bond: A covalent bond is formed when atoms share electrons in order to achieve a stable electron configuration. This type of bond usually occurs between non-metal atoms. In a covalent bond, two atoms share one or more pairs of electrons, creating a bond that holds them together. An example of a covalent bond is the formation of water (H2O). Two hydrogen (H) atoms share their electrons with one oxygen (O) atom, resulting in a molecule with two covalent bonds between the atoms.
Overall, the key difference between ionic and covalent bonds lies in the way electrons are shared or transferred between atoms.