Thorium has an average atomic mass of 232.0 and atomic number 90. in the space below draw a square from the periodic table to represent thorium?

Answer 1

The chemical symbol of thorium is Th. For the Periodic Table see this link.

Answer 2

Beta radiation is caused by two different reactions:

Beta Plus Decay:

n -> P+ e(-)+v

Where n is a neutron, P is a proton, e(-) is an electron and v is a neutrino (in this case an anti-neutrino)

and

Beta Minus Decay:

P -> n +e(+) +v

where e(+) is a positron

since atomic number is the number of protons, depending on the decay involved it will change by 1 or -1

Answer 3

There is no easy way to tell the number of neutrons an element might have, other then to look it up somewhere. Some references will give you the mass number, which is the total number of protons & neutrons. Also, most elements belong to a family of "isotopes" ,which is the same element with different numbers of neutrons. Usually the one you find in a reference is the one most abundantly found in nature. For example, the element Hydrogen can be found with 0 neutrons, with 1 neutron or with 2 neutrons. The most abundant isotope of Hydrogen is the one with 0 neutrons, but a large enough sample of Hydrogen will contain a few 1 neutron types. The 2 neutron types are rare because they are radioactive and after a short time change into Helium. A periodic table will give you the Atomic Mass of the atom. This is the total mass of the Neutrons & Protons. Since atomic masses of protons & neutrons are nearly equal you can find the mass number by rounding off the atomic mass to the nearest whole number. Then get the Neutron number by subtracting the atomic number. For example, Thorium has atomic mass 232.0381. Round this off to 232, then subtract 90 to get 142 neutrons.(for the most abundant isotope of Thorium). The number of neutrons depends on the isotope of the element; thorium has ca. 30 isotopes with different atomic masses (atomic mass rounded - atomic number 90 = number of neutrons).

Answer 4

The resulting element is protactinium, atomic number 91.

Answer 5

It decays to Radium with mass 86 and atomic number 88

Answer 6

Atomic number is 91

Answer 7

The number of protons remain unchanged.

Answer 8

In each case, two neutrons must be lost.