An object which experiences either a change in the magnitude or the direction of the velocity vector can be said to be accelerating. This explains why an object moving in a circle at constant speed can be said to accelerate - the direction of the velocity changes.
Answer:
C. transition elements
Explanation:
Transition elements are groups of metallic elements that have partially filled d orbitals. They occupy the d-block of the periodic table (Group 3-12). Examples of elements that fall under this category are Nickel (Ni), Cobalt (Co), Copper (Cu), Zinc (Zn) etc. Transition metals have outstanding properties that distinguishes them from other elements.
One of these properties is their ability to form colored compounds due to their unfilled d electron shells. They form ions that are usually colored in solid compounds and in solution.
I think silicon(Si) is the best example of semiconductors
Explanation:
Matter can be classified into two broad categories: pure substances and mixtures. ... A material composed of two or more substances is a mixture. Elements and compounds are both examples of pure substances. A substance that cannot be broken down into chemically simpler components is an elementOne useful way of organizing our understanding of matter is to think of a hierarchy that extends down from the most general and complex to the simplest and most fundamental (Figure 3.4.1 ). Matter can be classified into two broad categories: pure substances and mixtures. A pure substance is a form of matter that has a constant composition (meaning that it is the same everywhere) and properties that are constant throughout the sample (meaning that there is only one set of properties such as melting point, color, boiling point, etc. throughout the matter). A material composed of two or more substances is a mixture. Elements and compounds are both examples of pure substances. A substance that cannot be broken down into chemically simpler components is an element. Aluminum, which is used in soda cans, is an element. A substance that can be broken down into chemically simpler components (because it has more than one element) is a compound. For example, water is a compound composed of the elements hydrogen and oxygen. Today, there are about 118 elements in the known universe. In contrast, scientists have identified tens of millions of different compounds to date.
