The answer is sodium
Sodium has 11 protons (atomic number is 11) and has one valence electron. As the Bohr model diagram below shows, Sodium has 11 protons and 12 neutrons<span> in the nucleus to make the mass number 23. The 11 electrons necessary to make Sodium neutral (protons = electrons) are arranged in a pattern of 2-8-1.</span>
A chemical bond that involves the transfer of electrons from a metal to a nonmetal and thus forms ions and the atoms in the molecule are attracted towards each other through electrostatic force of attraction are said be ionic bond. In short, the bond formed between the two oppositely charged ions.
In salt, the compound formed between sodium and chlorine is sodium chloride having molecular formula 
where sodium is a metal and chlorine is the non-metal. The formation of the compound takes place by transfer of an electron from sodium thus forming a cation of formula 
to chlorine which gains electron and thus results in an anion formation having formula 
. The force of attraction between these oppositely charged ions that helds them together and results in formation of compound is electrostatic force of attraction.
Hence in salt, the nature of bond between sodium and chlorine is ionic.
Answer:
Demonstration 1 showed a chemical change because a new gaseous substance was formed, and demonstration 2 showed a physical change because liquid water became water vapor.
Explanation:
Chemical changes alter the chemical makeup of a subject, and a physical change only alters the appearance of a subject, not the chemical makeup.
Answer:
the answer is option (a).3
