1. carbon dioxide is a gas at low temperatures at mars because in the oxidizing environment organic compounds are oxidized to form carbon dioxide.
2. The 1 electron in outermost shell of Na is shared with 7 electrons of outermost shell of chlorine giving neutral charge on compound.
3. Electrostatic force of attraction is between the metal and non-metal.
4. When metal and non metal exchange electrons to form a neutral or no charge compound it is said to have form ionic bonds.
Explanation:
1. Temperature at Mars is very low -80 Fahrenheit (-60 degrees) because water is not present in the planet. Carbon dioxide is abundant in Mars. The atmosphere is oxidizing at Mars which oxidizes the organic compounds and forms carbon dioxide.
2. NaCl combines by sharing of electrons forming ionic bonding. Different atoms of the different element share electrons to form ionic bonds. Such bond is formed when electrons is transferred between the atoms. In the NaCl, Na has 1 electron (electropositive) in its outer shell and chlorine has 7 electrons (electronegative). Both share the electrons getting their octet complete and a neutral charge on the compound formed.
3. Electrostatic force of attraction is between the metal and non-metal when bond is formed. The ionic bonds is formed between metal and non metals when electron exchange takes place. The electrostatic force is the attraction between two opposite charges on the ion.
4. When a metal and non metal exchange electrons in which metal is electropositive and non metal is electronegative the bonds form is called ionic bond. The electron is transferred from metal to non metal and thus giving neutral charge on the compound i.e. the outer shell has its octet complete.
<u>Answer:</u>
<em>Silver tarnishing as the silver metal reacts with sulphur is a chemical change.</em>
<u>Explanation:</u>
Tarnishing is the process of chemical change occurring on the surface of objects leading to corrosion or other defects on the surface. The remaining options like dilution, eroding is a physical change where the concentration of salt and rock particles will be decreased, respectively.
Similarly for soil drying also the concentration of water will be decreased leading to a physical change from wetty or dry soil.
But the last option which indicates tarnishing of silver metal on reaction with sulphur is a chemical process as the surface of silver metal will be reacting to sulphur and leads to lose of electrons which leads to corrosion of the surface or tarnishing of silver.
It will be Oxygen . And total 8 protons, 8 electrons and 9 neutrons are present in it.
