How do halogens kill bacteria?

How do halogens kill bacteria?

Halogens. Other chemicals commonly used for disinfection are the halogens iodine, chlorine, and fluorine. Iodine works by oxidizing cellular components, including sulfur-containing amino acids, nucleotides, and fatty acids, and destabilizing the macromolecules that contain these molecules.

Why do halogens increase in boiling point?

The boiling points of halogens increase down the group due to the increasing strength of Van der Waals forces as the size and relative atomic mass of the atoms increase. This change manifests itself in a change in the phase of the elements from gas (F2, Cl2) to liquid (Br2), to solid (I2).

Which property is common to all halogens?

Halogens include solids, liquids, and gases at room temperature, and they vary in color. Halogens are among the most reactive of all elements. They have seven valence electrons, so they are very “eager” to gain one electron to have a full outer energy level.

What are the major properties of halogens?

Halogens share many similar properties including:

  • They all form acids when combined with hydrogen.
  • They are all fairly toxic.
  • They readily combine with metals to form salts.
  • They have seven valence electrons in their outer shell.
  • They are highly reactive and electronegative.

What are three properties of nonmetals?

Summary of Common Properties

  • High ionization energies.
  • High electronegativities.
  • Poor thermal conductors.
  • Poor electrical conductors.
  • Brittle solids—not malleable or ductile.
  • Little or no metallic luster.
  • Gain electrons easily.
  • Dull, not metallic-shiny, although they may be colorful.

What is the physical properties of halogens?

Group 17: Physical Properties of the Halogens

Property F Br
color pale yellow gas red-brown liquid
Density of liquids at various temperatures, /kg m-3 1.51 (85 °K) 3.19 (273 °K)
Melting point, /K 53.53 265.8
Boiling point, /K 85.01 331.93

What are the properties of lanthanides?

Lanthanides share the following common properties:

  • Silvery-white metals that tarnish when exposed to air, forming their oxides.
  • Relatively soft metals.
  • Moving from left to right across the period (increasing atomic number), the radius of each lanthanide 3+ ion steadily decreases.
  • High melting points and boiling points.

What are the properties of lanthanides and actinides?

All the lanthanide elements exhibit the oxidation state +3. Actinides are typical metals. All of them are soft, have a silvery color (but tarnish in air), and have relatively high density and plasticity.

Why lanthanides are called so?

They are called the lanthanides because they exhibit similar chemical properties to lanthanum, the first element in the group. Actinides are the 15 elements with atomic numbers from 89 to 103. They are named after the first element in the series, actinium.

What is the major difference between the lanthanides and actinides?

Actinides are radioactive elements. Lanthanides are non-radioactive elements with some exceptions. The main difference between actinides and lanthanides is that actinides can form complexes easily whereas lanthanides do not form complexes easily.

Who discovered lanthanides and actinides?


Which two actinides occur naturally on Earth?

All actinides are radioactive and release energy upon radioactive decay; naturally occurring uranium and thorium, and synthetically produced plutonium are the most abundant actinides on Earth.

How are actinides used?

A large number of actinides are used for the defense operations, nuclear weapons and for the production of energy. Plutonium is used in nuclear reactors and for nuclear bombs as well. Many of the actinide elements are used in the nuclear power plant and also for the production of electronic power.

Is terbium an actinide?

The valence electrons of the terbium element enter into 4f-orbital so the terbium is not an actinide. It is a lanthanide.

What are examples of lanthanides?

The lanthanides include the metals cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

What is the other name of lanthanides?

Lanthanoid, also called lanthanide, any of the series of 15 consecutive chemical elements in the periodic table from lanthanum to lutetium (atomic numbers 57–71). With scandium and yttrium, they make up the rare-earth metals.