What is calciums atomic mass

Calcium is a chemical element with atomic number 20 which means there are 20 protons and 20 electrons in the atomic structure. The chemical symbol for Calcium is Ca.

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Atomic Mass of Calcium
Density of Calcium
Calcium – Properties Summary
Calcium in Periodic Table

Since the number of electrons is responsible for the chemical behavior of atoms, the atomic number identifies the various chemical elements.

How does the atomic number determine the chemical behavior of atoms?

Atomic Mass of Calcium

Atomic mass of Calcium is 40.078 u.

Note that each element may contain more isotopes. Therefore this resulting atomic mass is calculated from naturally-occurring isotopes and their abundance.

The unit of measure for mass is the atomic mass unit (amu). One atomic mass unit is equal to 1.66 x 10-24 grams. One unified atomic mass unit is approximately the mass of one nucleon (either a single proton or neutron) and is numerically equivalent to 1 g/mol.

For 12C, the atomic mass is exactly 12u, since the atomic mass unit is defined from it. For other isotopes, the isotopic mass usually differs and is usually within 0.1 u of the mass number. For example, 63Cu (29 protons and 34 neutrons) has a mass number of 63, and an isotopic mass in its nuclear ground state is 62.91367 u.

There are two reasons for the difference between mass number and isotopic mass, known as the mass defect:

The neutron is slightly heavier than the proton. This increases the mass of nuclei with more neutrons than protons relative to the atomic mass unit scale based on 12C with equal numbers of protons and neutrons.
The nuclear binding energy varies between nuclei. A nucleus with greater binding energy has lower total energy, and therefore a lower mass according to Einstein’s mass-energy equivalence relation E = mc2. For 63Cu, the atomic mass is less than 63, so this must be the dominant factor.

The atomic mass number determines especially the atomic mass of atoms. The mass number is different for each different isotope of a chemical element.

How does the atomic mass determine the density of materials?

Density of Calcium

Density of Calcium is 1.55g/cm3.

Typical densities of various substances at atmospheric pressure.

Density is defined as the mass per unit volume. It is an intensive property, which is mathematically defined as mass divided by volume:

ρ = m/V

In other words, the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance. The standard SI unit is kilograms per cubic meter (kg/m3). The Standard English unit is pounds mass per cubic foot (lbm/ft3).

Calcium – Properties Summary

Element	Calcium
Atomic Number	20
Symbol	Ca
Element Category	Alkaline Earth Metal
Phase at STP	Solid
Atomic Mass [amu]	40.078
Density at STP [g/cm3]	1.55
Electron Configuration	[Ar] 4s2
Possible Oxidation States	+2
Electron Affinity [kJ/mol]	2.37
Electronegativity [Pauling scale]	1
1st Ionization Energy [eV]	6.1132
Year of Discovery	1808
Discoverer	Davy, Sir Humphry
Thermal properties
Melting Point [Celsius scale]	842
Boiling Point [Celsius scale]	1484
Thermal Conductivity [W/m K]	200
Specific Heat [J/g K]	0.63
Heat of Fusion [kJ/mol]	8.54
Heat of Vaporization [kJ/mol]	153.3

Calcium in Periodic Table

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Isotope	Atomic mass (Da)	Isotopic abundance (amount fraction)
40Ca	39.962 5909(2)	0.969 41(156)
42Ca	41.958 618(1)	0.006 47(23)
43Ca	42.958 766(2)	0.001 35(10)
44Ca	43.955 482(2)	0.020 86(110)
46Ca	45.953 69(2)	0.000 04(3)
48Ca	47.952 5229(6)	0.001 87(21)

In 1983, the Commission with its liberalized policy on uncertainties, was able to recommend as standard atomic weight Ar(Ca) = 40.078(4) weighted toward the mass-spectrometric measurements. Moreover, the stated uncertainty includes all chemical, x-ray, and mass-spectrometric measurements believed to be significant by the Commission, as enumerated in its 1983 report.

There is evidence for minor isotope fractionation of calcium in Nature, causing variability of Ar(Ca) in normal sources that is within the uncertainty of the standard atomic weight. Variations in n(44Ca)/n(40Ca) can be reported as δ44Ca values relative to the calcium carbonate reference material NIST-SRM 915a. A recent compilation yielded a range of published δ44Ca values in natural samples from a low of -2.17 ‰ in a cougar bone with Ar(Ca) = 40.0778 to a high of +2.76 ‰ in egg white with Ar(Ca) = 40.0784. Elemental calcium with as δ44Ca = -6.0 ‰ (Ar(Ca) = 40.0773) also has been reported. Variations in the isotopic composition of marine calcium have occurred over the last 80 Ma.

In addition, there are many reports of anomalous isotopic composition of some minor samples of Ca, some of which may have arisen from the decay of 40K to 40Ca. The annotation "g" is therefore maintained for this element. 41Ca is an extinct radioisotope (with a half-life of 0.1 Ma), which can be used to date the early history of the solar system through its decay to 41K.

SOURCE Atomic weights of the elements: Review 2000 by John R de Laeter et al. Pure Appl. Chem. 2003 (75) 683-800
© IUPAC 2003

CIAAW

Calcium
Ar(Ca) = 40.078(4) since 1983

The name derives from the Latin calx for "lime" (CaO) or "limestone" (CaCO3) in which it was found. It was first isolated by British chemist Humphry Davy in 1808 with help from the Swedish chemist Jöns Jacob Berzelius and the Swedish court physician M. M. af Pontin.

Isotopic reference materials of calcium.