Question

question 7 (1 point) question 7 of 25 | page 7 of 25 the elements in group 2 have similar chemical properties because each atom of these elements has the same - o a number of energy levels o b mass number o c number of valence electrons o d atomic number

Explanation:

Chemical properties are mainly determined by valence electrons. Elements in the same group have the same number of valence electrons, which leads to similar chemical properties. For example, Group 2 elements (alkaline earth metals) all have 2 valence electrons. They tend to lose these 2 electrons in chemical reactions, showing similar reactivity patterns.

• The number of energy levels (a) affects the atomic size and some physical properties but not the similarity in chemical properties across a group.
• The mass number (b) is related to the sum of protons and neutrons and has no direct relation to chemical properties.
• The atomic number (d) is the number of protons and determines the identity of the element, but it is the valence - electron configuration (related to the group number) that causes similar chemical properties.

Answer:

C. number of valence electrons