Question

practice: 1 identify the correct family 2 explain the reasoning based on valence electrons and/or properties
element description family? why?
barium (ba)- a reactive metal used in medical imaging and fireworks
iodine (i)- a dark purple solid that has 7 valence electrons
radon (rn)- a radioactive gas that is chemically nonreactive
strontium (sr)- a reactive metal with 2 valence electrons
cesium (cs)- a metal that reacts with water

1. multiple choice which of the following elements is in the same group as sodium (na)? a. oxygen (o) b. potassium (k) c. neon (ne) d. carbon (c)
2. short answer what do elements in the same group of the periodic table have in common?
3. multiple choice why do elements in the same group often react similarly? a. they have the same atomic number b. they are all metals c. they have the same number of valence electrons d. they are in the same period
4. short answer compare the chemical properties of chlorine (cl) and iodine (i). why are they similar?
5. short answer you wanted to conduct an experiment with sodium (na) and water, but you ran out of sodium. which element could you use in place of sodium that would react the same way. explain.

Explanation:

Step1: Recall periodic - table groups

Elements in the same group have similar properties due to the same number of valence electrons. Sodium (Na) is in Group 1 (alkali metals).

Step2: Analyze multiple - choice options for the first question

Potassium (K) is also in Group 1 like sodium. Oxygen (O) is in Group 16, Neon (Ne) is in Group 18, and Carbon (C) is in Group 14. So the answer to the first question is B. Potassium (K).

Step3: Answer the second question

Elements in the same group of the periodic table have the same number of valence electrons.

Step4: Analyze multiple - choice options for the third question

Elements in the same group react similarly because they have the same number of valence electrons. Atomic number is unique for each element, not all elements in a group are metals (e.g., Group 17 has non - metals), and being in the same period is not related to similar reactivity. So the answer is C.

Step5: Compare chlorine and iodine

Chlorine (Cl) and iodine (I) are both in Group 17 (halogens). They have 7 valence electrons, which gives them similar chemical properties such as being reactive non - metals and forming salts with metals.

Step6: Find a substitute for sodium

Potassium (K) can be used in place of sodium. Since both are in Group 1 (alkali metals), they have 1 valence electron and similar reactivity with water.

Answer:

1. B. Potassium (K)
2. They have the same number of valence electrons.
3. C. They have the same number of valence electrons
4. Chlorine and iodine are both in Group 17 (halogens) with 7 valence electrons, giving them similar chemical properties as reactive non - metals that form salts with metals.
5. Potassium (K) can be used. Both sodium and potassium are in Group 1 (alkali metals) with 1 valence electron, so they have similar reactivity with water.