**The Elements Adjusted by Newlands in the Same Slot**

John Newlands was a British chemist who proposed the Law of Octaves in 1863. According to this law, when elements are arranged in increasing order of their atomic masses, every eighth element exhibits similar properties. Newlands arranged the known elements at that time into rows of seven elements each, and the eighth element was similar to the first.

Two pairs of elements adjusted by Newlands in the same slot are:

1. Lithium (Li) and Sodium (Na):
- In Newlands' arrangement, lithium and sodium occupy the same slot.
- Lithium has an atomic mass of approximately 6.9, while sodium has an atomic mass of approximately 22.9.
- Both lithium and sodium are alkali metals, and they exhibit similar chemical and physical properties.
- They are highly reactive, have low melting and boiling points, and readily form compounds with other elements.
- Lithium and sodium are soft metals that can be cut with a knife, and they are both silvery-white in appearance.

2. Chlorine (Cl) and Potassium (K):
- Chlorine and potassium are also adjusted by Newlands in the same slot.
- Chlorine has an atomic mass of approximately 35.5, while potassium has an atomic mass of approximately 39.1.
- Both chlorine and potassium are highly reactive elements.
- Chlorine is a halogen and is a yellow-green gas at room temperature, while potassium is an alkali metal and is a soft, silvery-white solid.
- Chlorine and potassium readily form compounds with other elements, and they both have important functions in biological systems.

**Metalloids and Examples**

Metalloids, also known as semimetals, are elements that exhibit properties of both metals and nonmetals. They have characteristics of both groups and display intermediate properties. Two examples of metalloids are:

1. Silicon (Si):
- Silicon is a metalloid with atomic number 14.
- It is a gray, brittle solid at room temperature with a metallic luster.
- Silicon is a semiconductor, meaning it can conduct electricity under certain conditions but not as well as metals.
- It is an essential element in the electronics industry and is used extensively in the production of computer chips and solar cells.

2. Arsenic (As):
- Arsenic is another metalloid, belonging to Group 15 of the periodic table.
- It is a gray, brittle solid that can sublimate into a toxic vapor.
- Arsenic has both metallic and nonmetallic properties.
- It is used in various industries, including the production of semiconductors, pesticides, and wood preservatives.

Metalloids play a significant role in the development of technology and have diverse applications due to their unique properties. They bridge the gap between metals and nonmetals, exhibiting characteristics that allow for various practical uses.

In order to fit elements into his Table,Newland adjusted two elements in thesame slot, but also put some unlikeelements under the same note. Cobalt and nickel are in the same slot and these are placed in the same column as fluorine, chlorine and bromine whichhave very different properties than theseelements.