Water from oceans and seas contains dissolved salts, atmospheric gases, and inorganic matter. The density of water with dissolved substances is higher than pure water. Saltwater is water that contains dissolved salts. Water from oceans and seas is salty. About 70% of the earth’s surface is covered by water in the seas and oceans, which …
DNA analysis is one of the techniques used in forensic science. It is applied in paternity testing and the identification of crime suspects. A sample of cells from a crime scene is analyzed, and the results are compared with those of a suspect in a criminal investigation. In paternity testing, the DNA of a father …
On a humid day, we see clouds floating in the sky. Some clouds are white and sparsely scattered, while others are dark gray and heavy. There are four major types of clouds; stratus, nimbus, cirrus, and cumulus. Some clouds, such as stratus, form snow while others, such as nimbus, result in rainfall. Cumulus clouds appear …
During winter, we see snowfalls everywhere. When snowflakes accumulate over a long period, blocks of ice are formed. Some of the ice melts when the temperature rises in lower altitude areas. Ice in high-altitude areas can stay for a long time without melting because the temperatures are low. As the ice accumulates to form large …
Reports of fish raining from the skies have been frequently recurring. From ancient times up to more modern times, witnesses have continued to report such incidents. This brings to mind similar accounts in the Bible where frogs or gnats were transported in large numbers and deposited on homes during the showdown between Moses and Pharaoh …
DNA (deoxyribonucleic acid) has been described as the molecule of life. It has been found in the cells of all organisms that have ever been observed. But is it possible that we could have organisms with no DNA? So far, the organisms we know are just a fraction of all living organisms. Many more organisms …
When a truck sounding a horn approaches you, the horn’s pitch increases gradually and is highest as the truck passes near you. As the truck recedes, the pitch gradually decreases. The variation in sound as the source approaches the receiver and as it moves away is caused by the Doppler Effect. The Doppler Effect, also …
(a) neutrons (b) electrons (c) protons (d) neutrons and protons (e) protons, neutrons, and electrons. The Correct answer is (c) Protons Explanation Atoms of the same element have the same number of protons in their nucleus. Let’s break it down… The number of protons in an atom is also called its atomic number. Now, atomic …
Colors give our surroundings a rich appearance but how are they actually produced for us to see them? The part of the electromagnetic spectrum (EMS) that our eyes can see is what we call light. But visible light (i.e., white light) is itself made up of a spectrum of 7 lights of different colors. These …
a. γ−rays b. visible light c. ultraviolet radiation d. infrared radiation e. visible red light f. visible blue light g. All of these have the same energy. Answer: The answer is (a) γ−rays (gamma rays) Explanation: Radiation is a form of energy that is transmitted through space or other media as waves. For light, this …
