That the physical and chemical properties of the elements are periodic within the sequence of their atomic numbers. the law of conservation of mass newton’s 1st law thermodynamic law the periodic law

Option (d) is the correct answer.

Explanation:

According to the periodic law, physical and chemical properties of elements occur periodically when elements are placed according to the sequence of their atomic numbers.

For example, elements of a group show similar chemical properties as they have same number of valence electrons.

Elements of a period 3 show different characteristics and these characteristics are periodically repeated by elements of period 4.

Therefore, we can conclude that the Periodic law states that the physical and chemical properties of the elements are periodic within the sequence of their atomic numbers.

10 years is the answer

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.