A common isotope of iron (Fe) has an atomic number of 26 and a mass number
of 56. The total number of subatomic particles in the nucleus is: *
26

82

Explanation:

Atomic number of the isotope is 26 and it has a mass number of 56

X = ⁵⁶₂₆Fe

The three main subatomic particles in an atom are

1. Proton

2. Neutron

3. Electron

The number of protons and electrons are usually equal so as to maintain electrical neutrality in the atom except in cases where it's a charged particles hence the number of proton and electrons will differ.

In this case, the atomic number is 26 and atomic numbers are also known as the number of protons (positively charged particle).

Proton = 26

Electrons = 26 (since it's a naturally charged particle)

Neutron = ?

Mass number = sum of proton and neutrons. This variation in the mass number usually leads to isotopes of an atom and this is mainly caused by variation in the number of neutrons eg. Carbon-12 and Carbon-13 have different number of neutrons.

Mass number = protons + neutrons

Neutrons = mass number - protons

Neutrons = 56 - 26

Neutrons = 30

Subatomic particles present are

Protons = 26

Electrons = 26

Neutrons = 30

Total number = (26 + 26 + 30) = 82

The total number of subatomic particles is 82.

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).