What is the difference between brass and bronze?
Brass is an alloy of copper and zinc.
Bronze is a more durable mixture of copper and tin.
Smiling is easier on the face than frowning. It takes 17 muscles to smile and 43 to frown.
The earliest era of geologic time is the Precambrian age. It began when the earth’s crust formed, 4.6 billion years ago, and ended with the dawn of the Cambrian period, 570 million years ago. About seven-eighths of earth’s history since the formation of the crust took place during the Precambrian age.
About 100,000 hairs are on a human head. Human hairs grow about 0.01 inch every day.
The term plasma to a physician means the fluid part of blood, lymph, or milk as distinct from suspended matter. The term plasma to a physicist means a collection of negatively charged electrons and positively charged ions, existing in about equal numbers in a neutral state; plasma is considered a fourth state of matter, distinct…
The plates (solid segments of the earth’s crust and upper mantle) that consist mostly of continents move at an average speed of about 2 centimeters per year. Europe and North America are moving apart at about this speed. The plates that are mostly under the oceans move faster, at an average speed of about 10…
Connecticut was number one in 1987 with $20,980. At the bottom was Mississippi with $10,204. The average per-capita personal income in the United States as a whole was $15,340.