Eriq, a chemist, is running tests with four unknown elements. He has found that they all bond the same way, so he knows that they are in the same group on the periodic table of elements. The table shows other properties that Eriq observed.

Question

A 4-column table with 4 rows titled properties of four unknown elements. The first column titled element number has entries 1, 2, 3, 4. The second column titled melting point has entries 266 K, 172 K, 387 K, 53 K. The third column titled boiling point has entries 332 K, 239 K, 457 K, 85 K. The fourth column titled phase at room temperature has entries liquid, gas, solid, gas.

These four elements are most likely in group

15.
17.
18.

Answer 1

Based on the properties provided, we can analyze the unknown elements to help determine which group on the periodic table they belong to.

1. Melting and Boiling Points: The elements have a wide range of melting and boiling points, indicating different states and properties at room temperature.

2. Phase at Room Temperature: The phases of the elements at room temperature are as follows:

   • Element 1: liquid
   • Element 2: gas
   • Element 3: solid
   • Element 4: gas

Now, let's consider the groups mentioned:

• Group 15 (Nitrogen Group): This group includes elements like nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). Typically, nitrogen is a gas, phosphorus is a solid, arsenic is a solid, antimony is a solid, and bismuth is a solid metal. The presence of both gases and a solid element could indicate members from this group.

• Group 17 (Halogens): This group contains fluorine (F, gas), chlorine (Cl, gas), bromine (Br, liquid), and iodine (I, solid). The halogens also exhibit a pattern where fluorine and chlorine are gases, bromine is a liquid, and iodine is a solid.

• Group 18 (Noble Gases): This group consists of gases (e.g., helium, neon, argon) which do not exhibit melting or boiling points in the conventional sense, as they remain gaseous under standard conditions.

Given the information, particularly the phases at room temperature, it is most consistent with Group 17 (the halogens), as it includes gases (elements 2 and 4), a liquid (element 1), and a solid (element 3) at room temperature.

So, the four unknown elements are most likely in Group 17.