Why is technetium atomic mass in brackets?

Why is technetium atomic mass in brackets?

If an element has no stable isotopes, meaning that all known isotopes of that element will undergo nuclear decay, the atomic number is displayed in parentheses.

What do the brackets around an element mean?

Very often in chemical formulae, we use parentheses to form subgroups of atoms within a molecule. In such a formula, the subscript outside the parentheses means that to count atoms, you must multiply that subscript by the numbers of atoms inside.

Why are some atomic weights in brackets?

The atomic weight of an element is based on the variety of naturally occurring isotopes of that element and the relative abundance of each. The number in parentheses is the mass number of the most stable or best-known isotope of that element. Atomic weights are measured in atomic mass units.

What is technetium on the periodic table?

technetium (Tc), chemical element, synthetic radioactive metal of Group 7 (VIIb) of the periodic table, the first element to be artificially produced.

Why technetium and promethium have whole number atomic masses and have a bracket symbol on the periodic table?

Periodic table of elements consists of elements with stable and unstable nucleus. But the atomic mass of elements like technetium and promethium have whole number atomic masses and have a bracket symbol on the periodic table because these elements consists of unstable, radioactive isotopes.

Why is hydrogen in Group 1 if it is not a metal?

Hydrogen is a nonmetal and is placed above group in the periodic table because it has ns1 electron configuration like the alkali metals. However, it varies greatly from the alkali metals as it forms cations (H+) more reluctantly than the other alkali metals.

Do brackets mean molarity?

Molarity is defined as the number of moles of solute per liter of solution. The symbol for molarity is M or moles/liter. Chemists also use square brackets to indicate a reference to the molarity of a substance. For example, the expression [Ag+] refers to the molarity of the silver ion in solution.

What does brackets mean in chemistry?

5 Enclosing marks. Parentheses (round brackets, curves), square brackets, and braces (curly brackets) are used in chemical nomenclature to set off parts of a name dealing with specific structural features in order to convey the structure of a compound as clearly as possible.

What is technetium used for?

Technetium (Tc-99m) is an isotope commonly used in a number of medical diagnostic imaging scans. Tc99m is used as a radioactive tracer for nuclear medicine; which is a form of medical imaging that assesses how particular parts of our body are working or functioning.

What is technetium made of?

Technetium was created by bombarding molybdenum atoms with deuterons that had been accelerated by a device called a cyclotron. Today, technetium is produced by bombarding molybdenum-98 with neutrons. Molybdenum-98 becomes molybdenum-99 when it captures a neutron.

Why is there a section at the bottom of the periodic table?

The lanthanides and actinides are separated from the rest of the periodic table, usually appearing as separate rows at the bottom. The reason for this placement has to do with the electron configurations of these elements.

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