Answer:
the number of neutrons in the nucleus
Explanation:
The mass number 205 is the total number of protons and neutrons in the nucleus. Lead has 82 protons, so a mass number of 205 indicates a nucleus with 123 neutrons.
Similarly, the mass number 208 indicates a lead nucleus with 126 neutrons.
The difference in atomic structure is the difference in the number of neutrons in the nucleus.
The first one has 35 atoms and the elements hydrogen, oxygen and chlorine
The second one has 9 atoms and the elements sodium, carbon, and helium
Answer:
2 atoms of nitrogen are present.
The periodic table of elements is divided into columns and rows. The vertical columns represent the groups while the horizontal rows represent the periods. A group of elements usually have similar physical and chemical properties. The first column of the periodic table is made up of 7 elements including SODIUM.
1. The name of the element chosen is sodium and its chemical symbol is Na.
2. Sodium is a metal and thus it has metallic properties.
3. Sodium belongs to group one elements whose family name is ALKALI METALS.
4. The neutral atom of sodium is made up of 11 protons, 11 electrons and 12 neutrons.
Sodium chloride is the chemical name for salt and is composed of sodium and chlorine, so it is a compound.
