Explanation:
A property that leads to changes in chemical composition of a substance is known as chemical property. So, when we move down a group in periodic table then chemical properties of the elements remain the same.
This is because elements of the same group tend to have same number of valence electrons. Therefore, they have similar reactivity which leads to change in their chemical composition upon reaction with another substance.
For example, lithium (Li) and potassium (K) are both group 1 elements. And, phosphorous (P) and arsenic (As) are both group 15 elements.
Thus, we can conclude that pair of Li and K will show similar chemical properties. Also, pair of P and As will show similar chemical properties.
