Question

(Answer this in a 10th grade level response)You've navigated all across the periodic table, you used clues and hints to solve for many elements. The last piece of the puzzle is the most challenging! It will come in two parts:

First: Identify the element from clue 16 ---- Period 6, Group 1. (Name and Atomic number, please 2 points)

Second: you must "cross a divide".

When you land back on "solid ground" there is a silvery white metal with an average mass of 178.5 amu.

From there --- add 7 protons! Identify the element and describe the final steps you used to solve this last clue! (4 points)

Answer 1

### First Part:
The element from clue 16, which is in Period 6 and Group 1 of the periodic table, is **Cesium**. Its atomic number is **55**.

### Second Part:
To "cross a divide," we might be looking at a change or a transition between different categories of elements. When we land on "solid ground," we're looking for a silvery-white metal that has an average atomic mass of **178.5 amu**. This element is **Tungsten**, which has an atomic number of **74**.

Now, when we "add 7 protons" to Tungsten's atomic number of 74, we get:
74 + 7 = 81.

The element with atomic number **81** is **Thallium**.

### Final Steps:
1. I identified the element from clue 16 as Cesium (atomic number 55) based on its position in the periodic table.
2. I then looked for a silvery white metal with an atomic mass of approximately 178.5, which is Tungsten with an atomic number of 74.
3. Finally, I added 7 protons to the atomic number of Tungsten (74), giving me Thallium with atomic number 81.

So, to summarize: Cesium (Atomic number 55), Tungsten (Atomic number 74), and then Thallium (Atomic number 81) after adding 7 protons.