Radium is an alkaline earth metal and was discovered in 1898 by Marie and Pierre Curie. It is a lustrous metal and is widely used in various industry.

• Element With Atomic Number 88
• Atomic Number 88 Crossword Clue
• Atomic Number 88 Meaning

Discovery and history

• Atomic Number: 88: Atomic Radius: 283 pm (Van der Waals) Atomic Symbol: Ra: Melting Point: 700 °C: Atomic Weight: 226: Boiling Point: 1737 °C: Electron Configuration.
• What is the metal for atomic number 88 - Answered by a verified Tutor We use cookies to give you the best possible experience on our website. By continuing to use this site you consent to the use of cookies on your device as described in our cookie policy unless you have disabled them.

Radium was discovered in 1898 by Marie and Pierre Curie (a Polish and French chemist, respectively) [1]. They isolated pure radium in 1911, via electrolysis of radium chloride. Today, radium can be obtained as a byproduct of refining uranium and is usually sold as radium chloride (RaCl₂) or radium bromide (RaBr₂) and not as a pure material.

Radium

Occurrence

In nature, radium is found in uranium and thorium ores in trace amounts as small as a seventh of a gram per ton of uraninite. Due to the high solubility of its compounds in water, radium is extracted by successive lixiviation of the referred ores. [2] Radium has an abundance in the Earth’s crust by weight about 1 part per trillion. This makes it the 84^thmost abundant element. Radium originally found in pitchblende ore. It was derived from Latin word radius which means rays.

Physical characteristics

Chemical elements listed by atomic number The elements of the periodic table sorted by atomic number. Click on any elements name for further chemical properties, environmental data or health effects. This list contains the 118 elements of chemistry. With atomic number 88, it has four natural isotopes of atomic weight 228, 226, 224 and 223 - though there are a remarkable 21 more artificial isotopes. A later starring role for radium would be as the source of alpha particles - helium nuclei - used by Rutherford in 1909 at the Cavendish laboratory in Cambridge to fire at a thin gold foil.

Radium is a radioactive element of the alkaline earth series of metals. Radium is silvery, lustrous, soft and radioactive element. Its atomic symbol Ra, atomic number 88, atomic weight 226, solid at room temperature. Melting point 700 C and boiling point 1140 C. It is 6^th element in group 2 of periodic table. Radium has density 5.5g/cm³ higher than barium.

Chemical characteristics

Radium readily oxidizes on exposure to air, and is turned from almost pure white to black. Radium is luminescent, corrodes in water to form radium hydroxide. Although is the heaviest member of the alkaline-earth group it is the most volatile. [3] It forms the colorless Ra²⁺ cation in aqueous solution, which is highly basic and does not form complexes readily. Its compounds display a faint bluish glow in the dark, due to its radioactivity and the electrons release their energy as light when they are de-excited. It is interacted by water with vigorous evolution of hydrogen and by air with the formation of the nitride. It occurs exclusively as the Ra²⁺ ion in all its compounds. The sulfate, RaSO₄, is the most insoluble sulfate known, and the hydroxide, Ra (OH)₂, is the most soluble of the alkaline-earth hydroxides. Radium and its salts show luminescence and impart a carmine color to flame. Being radioactive it emits alpha and beta particles as well as gamma rays when mixed with beryllium it produces neutron. Most radium compounds are simple ionic compound.

Uses

• Radium is used in luminous paint.
• Used in medicine to produce radon gas.
• Radium and beryllium were once used as a portable source of neutrons.
• Radium isotopes are used for cancer treatment
• Radium is used as additive in products like toothpaste, hair creams and even food items.
• As additive in products like toothpaste, hair creams,
• It is used in various physics experiments.

Salt of Radium

• Radium hydroxide: Readily soluble among alkaline hydroxide
• Radium chloride: Colorless luminous compound, it becomes yellow after some time due to self-damage by the alpha radiation.
• Radium bromide: Colorless luminous compound that is soluble in water.
• Radium nitrate: White compound that can be made by dissolving radium carbonate in nitric oxide. Radium forms many insoluble salts, including sulfate, chromate, carbonate, iodate, and nitrate.

Health effects

Like radioactive elements radium is a dangerous substance to handle. It gives off radiation which can kill living cells. This property is desirable in treating cancer. Killing cancer cells can help a patient recover from the disease. But great care must be taken in using radium for this purpose. Its radiation can also kill healthy cells. [6] Radium levels in drinking water may be high when it is extracted from deep wells that are located near radioactive waste disposal sites. Exposure to higher levels of radium may result in health effects, such as teeth fracture, anemia and cataract. [7]

Isotopes

Around 33 isotopes have been discovered with mass number ranging from Ra 202 to 234. But there are four naturally occurring isotopes, including Radium -223, Radium -224, Radium- 226, Radium- 228. The most stable isotope is radium-226, with a half-life of about 1600 years. It decays into radon-222 through alpha decay or into lead-212 by ejecting a carbon-14 nucleus. [5]

References

Other Periodic Table Elements

• Francium

  Francium was discovered in 1939. It is very unstable alkali metal and considered the second…

• Tennessine

  Tennessine is a synthetic element that was discovered in 2010. It is highly radioactive and…

• Bohrium

  Bohrium was discovered in 1976 in Russia. It is radioactive and an artificially prepared element.…

Learning Outcomes

• Define atomic and mass numbers.
• Determine the number of protons, neutrons, and electrons in an atom.
• Identify the charge and relative mass of subatomic particles.
• Label the location of subatomic particles in the atom.
• Determine the mass of an atom based on its subatomic particles.
• Write A/Z and symbol-mass format for an atom.

Atoms are the fundamental building blocks of all matter and are composed of protons, neutrons, and electrons. Because atoms are electrically neutral, the number of positively charged protons must be equal to the number of negatively charged electrons. Since neutrons do not affect the charge, the number of neutrons is not dependent on the number of protons and will vary even among atoms of the same element.

Atomic Number

The atomic number (represented by the letter Z)of an element is the number of protons in the nucleus of each atom of that element. An atom can be classified as a particular element based solely on its atomic number. For example, any atom with an atomic number of 8 (its nucleus contains 8 protons) is an oxygen atom, and any atom with a different number of protons would be a different element. The periodic table (see figure below) displays all of the known elements and is arranged in order of increasing atomic number. In this table, an element's atomic number is indicated above the elemental symbol. Hydrogen, at the upper left of the table, has an atomic number of 1. Every hydrogen atom has one proton in its nucleus. Next on the table is helium, whose atoms have two protons in the nucleus. Lithium atoms have three protons, beryllium atoms have four, and so on.

Since atoms are neutral, the number of electrons in an atom is equal to the number of protons. Hydrogen atoms all have one electron occupying the space outside of the nucleus. Helium, with two protons, will have two electrons. In the chemical classroom, the proton count will always be equivalent to an atom's atomic number. This value will not change unless the nucleus decays or is bombarded (nuclear physics).

Mass Number

Experimental data showed that the vast majority of the mass of an atom is concentrated in its nucleus, which is composed of protons and neutrons. The mass number (represented by the letter A)is defined as the total number of protons and neutrons in an atom. Consider the table below, which shows data from the first six elements of the periodic table.

Consider the element helium. Its atomic number is 2, so it has two protons in its nucleus. Its nucleus also contains two neutrons. Since (2 + 2 = 4), we know that the mass number of the helium atom is 4. Finally, the helium atom also contains two electrons, since the number of electrons must equal the number of protons. This example may lead you to believe that atoms have the same number of protons and neutrons, but a further examination of the table above will show that this is not the case. Lithium, for example, has three protons and four neutrons, giving it a mass number of 7.

Knowing the mass number and the atomic number of an atom allows you to determine the number of neutrons present in that atom by subtraction.

[text{Number of neutrons} = text{ rounded mass number} - text{atomic number}]

Atoms of the element chromium (left( ce{Cr} right)) have an atomic number of 24 and a mass number of 52. How many neutrons are in the nucleus of a chromium atom? To determine this, you would subtract as shown:

[52 - 24 = 28 : text{neutrons in a chromium atom}]

The composition of any atom can be illustrated with a shorthand notation called A/Z format. Both the atomic number and mass are written to the left of the chemical symbol. The 'A' value is written as a superscript while the 'Z' value is written as a subscript. For an example of this notation, look to the chromium atom shown below:

[ce{^{52}_{24}Cr}]

Another way to refer to a specific atom is to write the mass number of the atom after the name, separated by a hyphen. Symbol-mass format for the above atom would be written as Cr-52. In this notation, the atomic number is not included. You will need to refer to a periodic table for proton values.

Example (PageIndex{1})

Calculate each of the three subatomic particles and give specific group or period names for each atom.

1. mercury
2. platinum
3. bromine

Solutions

1. Hg (transition metal)- has 80 electrons, 80 protons, and 121 neutrons
2. Pt (transition metal)- has 78 electrons, 78 protons, and 117 neutrons
3. Br (halogen)- has 35 electrons, 35 protons, and 45 neutrons

Example (PageIndex{2})

Write both A/Z and symbol-mass formats for the atoms in Example (PageIndex{1}).

Solutions

1. (ce{^{201}_{80}Hg}) and Hg-201
2. (ce{^{195}_{78}Pt}) and Pt-195
3. (ce{^{80}_{35}Br}) and Br-80

Example (PageIndex{3})

Identify the elements based on the statements below.

1. Which element has 25 protons?
2. Which element has 0 neutrons?
3. Which element has 83 electrons?

Solutions

a. manganese

b. hydrogen

Element With Atomic Number 88

c. bismuth

Need More Practice?

Atomic Number 88 Crossword Clue

• Turn to section 3.E of this OER and answer questions #1-#2, #4, and #8.

Contributors and Attributions

Atomic Number 88 Meaning

• CK-12 Foundation by Sharon Bewick, Richard Parsons, Therese Forsythe, Shonna Robinson, and Jean Dupon.

• Allison Soult, Ph.D. (Department of Chemistry, University of Kentucky)