The chemical element thulium is classed as a lanthanide and rare earth metal….Data Zone.

Thulium is a lanthanide element, it has a bright silvery-gray luster and can be cut by a knife. It is the least abundant of the rare earths and its metal is easy to work.

The group 13 elements consist of six elements. They are boron (B), aluminium (Al), gallium (Ga), Indium (In), thallium (Tl), and element 113. The commonest property of the group is that each one of the elements has three electrons in the outer shell of their nuclear structure.

Californium is not only useful as a neutron source, but it’s the most valuable element that exists, per unit mass. Out of the naturally-occurring elements, astatine is pretty useless, as there’s less than 30 grams of it at any moment on Earth.

Nonmetals include the nonmetal group, the halogens, and the noble gases. These elements have similar chemical properties to each other that distinguish them from the elements that are considered metals….List of Nonmetals.

So, if we include the nonmetals group, halogens, and noble gases, all of the elements that are nonmetals are:

• Hydrogen (sometimes)
• Carbon.
• Nitrogen.
• Oxygen.
• Phosphorus.
• Sulfur.
• Selenium.
• Fluorine.

The 17 nonmetal elements are: hydrogen, helium, carbon, nitrogen, oxygen, fluorine, neon, phosphorus, sulfur, chlorine, argon, selenium, bromine, krypton, iodine, xenon, and radon.

Chemically, hydrogen, carbon, nitrogen, oxygen, phosphorus, arsenic and selenium are the non-metallic elements in the periodic table.

Most elements on the periodic table are metals….List of Metals.

Answer: Alloys such as medium and high carbon steel, cast iron and tool steel are brittle. Metals like gold, copper, lead and silver are the opposite – ductile.

Imagine the difference between breaking glass (brittle) and pulling apart taffy (ductile). With that definition there are brittle metals, like cast iron, and non-brittle metals like gold.

steel. …is the hardest and most brittle form of steel. Tempering martensitic steel—i.e., raising its temperature to a point such as 400° C and holding it for a time—decreases the hardness and brittleness and produces a strong and tough steel.