Question

learning target
i can identify patterns on the periodic table and use them to predict properties of elements.
4a. which element would be more electronegative, potassium (k) or calcium (ca)? justify your choice by discussing how the periodic table is arranged and the patterns that can be observed. (2 points)
is more electronegative. this is because it is located in group and has an atomic number of . having a atomic number means that it has protons in the nucleus. the difference in nuclear charge leads to attraction of the electrons to the nucleus, increasing electronegativity.
4b. the metals from group ii reacted according to the table below

	carbonate	sulfate	iodate
calcium	forms a cloudy, white powder	no reaction	no reaction
strontium	reacts and turns white	reacts and turns white	no reaction
barium	quickly reacts a white cloudy solution. solid settles on the bottom	reacts and forms a white solid/powder	forms a white solid/powder the iodate only reacted with the barium

Explanation:

Step1: Recall electronegativity trend

Electronegativity increases across a period from left - to - right on the periodic table. Potassium (K) is in group 1 and has atomic number 19, while calcium (Ca) is in group 2 and has atomic number 20.

Step2: Analyze the elements

Since calcium has a higher atomic number (more protons in the nucleus), it has a greater nuclear charge. This leads to a stronger attraction of the electrons to the nucleus, increasing electronegativity.

Step3: Answer 4b

Based on the table, we can observe trends in reactivity of group II metals with different anions. As we go down the group (from magnesium to barium), the reactivity increases.

Answer:

4a. Calcium; 2; 20; higher; more; stronger
4b. As we go down group II, the reactivity of metals with carbonate, sulfate and iodate generally increases. Magnesium shows no reaction with any of them, calcium reacts with carbonate, strontium reacts with carbonate and sulfate, and barium reacts with all three.