Which statement about tempered glass is true?

Which statement about tempered glass is true?

• A. It shatters with a center punch
• B. It remains intact
• C. It melts
• D. It floats

Answer: (A)

Tempered glass is heat-treated to put the outer surfaces in compression, so when it fails it breaks into many small, dull-edged pieces rather than forming large, dangerous shards. That’s why a center punch typically causes tempered glass to shatter rather than stay intact. The other statements don’t fit the behavior of tempered glass: it doesn’t remain intact under impact, it doesn’t melt at normal temperatures, and it doesn’t float. In vehicles, side and rear windows are usually tempered, which is why their failure pattern is rapid shattering when struck.

Tempered glass is heat-treated to put the outer surfaces in compression, so when it fails it breaks into many small, dull-edged pieces rather than forming large, dangerous shards. That’s why a center punch typically causes tempered glass to shatter rather than stay intact. The other statements don’t fit the behavior of tempered glass: it doesn’t remain intact under impact, it doesn’t melt at normal temperatures, and it doesn’t float. In vehicles, side and rear windows are usually tempered, which is why their failure pattern is rapid shattering when struck.