In the following 2X2 crossword, each letter must be

QUESTION:

In the following \(2 \times 2\) crossword, each letter must be correct four ways: horizontally, vertically, diagonally, and by itself. When the puzzle is complete, the four spaces will contain the overlapping symbols of 10 elements. Use capital letters for each square. There is only one correct solution.*

Horizontal

1-2: Two-letter symbol for a metal used in ancient times

3-4: Two-letter symbol for a metal that burns in air and is found in Group 5A

Vertical

1-3: Two-letter symbol for a metalloid

2-4: Two-letter symbol for a metal used in U.S. coins

Single Squares

1: A colorful nonmetal

2: A colorless gaseous nonmetal

3: An element that makes fireworks green

4: An element that has medicinal uses

Diagonal

1-4: Two-letter symbol for an element used in electronics

2-3: Two-letter symbol for a metal used with \(\mathrm{Zr}\) to make wires for superconducting magnets