science & technology Online Quiz - 467

Napster, founded by Shawn Fanning and Sean Parker in 1999, was the first peer-to-peer file sharing service that popularized MP3 exchange. It revolutionized digital music distribution before facing legal challenges. BitTorrent and eMule came later.

Oracle announced its acquisition of Sun Microsystems in April 2009. The deal faced regulatory review and was approved by the US and EU authorities, completing in January 2010. This acquisition gave Oracle control over Java, MySQL, and Sun's hardware business. The question has grammatical errors but the facts are correct.

Hydrogen is the most abundant element in the universe, making up about 75% of all normal matter by mass. It was formed in the Big Bang and is the primary fuel in stars. Helium is the second most abundant, while oxygen and iron are much more common on Earth but rare in the universe as a whole. The question has a typo ('abundent' should be 'abundant').

Blackcomb was the codename for a version of Windows that was planned after Vista. The project was eventually canceled and its features were rolled into Windows 7 (codenamed Vienna/Blackcomb). Blackcomb never shipped as a standalone Windows version.

The normal resting heart rate for adults is 60-100 beats per minute according to medical standards. Option A correctly states this range. Option B incorrectly narrows it, while Option C suggests rates above 100 which would be tachycardia (abnormally fast), and Option D is vague but would exclude normal rates above 100.

Children typically have higher pulse rates than adults, with 70-100 beats per minute being the normal range. This is physiologically correct as children's faster metabolism requires a higher heart rate. Option A (60-100) is too broad, Option C (80-100) is too narrow, and Option D (60-80) is too low for children.

The normal blood pressure reading is 120/80 mmHg, which is considered the standard healthy blood pressure. This represents systolic pressure of 120 and diastolic pressure of 80. The other options are incorrect: 140/90 is considered high/prehypertension, 120/89 doesn't follow standard notation, and 140/80 is not the normal reading.

On average, the human eye blinks about 12-15 times per minute, though this can vary based on conditions. Option C (12 times) is closest to the scientific average. The other options overestimate this rate significantly.

The normal pulse rate for adults is 60-100 beats per minute, which is the medically accepted range for a healthy resting heart rate. Option A (70-100) is too narrow, Option B (80-100) is even more restrictive, and Option D (90-100) is abnormally narrow and would exclude most healthy adults.

The normal resting heart rate for adults is 60-100 beats per minute. This range applies to healthy adults at rest. Options B and D are incorrect because they exclude the normal lower end, while option C only describes an elevated rate.

Children typically have a higher normal pulse rate than adults, ranging from 70-100 beats per minute. This reflects their faster metabolism and smaller heart size. Option A is the adult range, while C and D are too narrow.

The standard normal blood pressure is 120/80 mmHg (systolic/diastolic). This is considered the optimal reading for healthy adults. Option A (140/90) represents hypertension, while C and D are not standard reference values.

On average, a human eye blinks about 12-15 times per minute to keep the eye moist and clean. Blinking rate varies with activities like reading (less blinking) versus talking (more blinking). Options A, B, and D are incorrect estimates.

The normal resting pulse rate for adults is 60-100 beats per minute. This is the standard medical reference range for healthy adults at rest. Options A and B are incorrect ranges, while D is too narrow.

French physicists Charles Fabry and Henri Buisson discovered the ozone layer in 1913 through spectroscopic methods. They observed that certain wavelengths of solar radiation were absorbed by atmospheric ozone, identifying this protective layer in the stratosphere.

Ozone is an allotrope of oxygen consisting of three oxygen atoms (O3). Unlike the more common diatomic oxygen (O2) we breathe, ozone is a powerful oxidizing agent found primarily in the stratosphere where it forms the protective ozone layer.

CFCs (chlorofluorocarbons) were widely used as refrigerants in refrigerators and air conditioning systems before their ozone-depleting effects were discovered. They were also used in aerosol sprays, but refrigeration was a major application.

The primary greenhouse gases are carbon dioxide (CO2), water vapor (H2O), nitrous oxide (N2O), and methane (CH4). These gases trap heat in Earth's atmosphere through the greenhouse effect. Options A, B, and D contain incorrect chemical formulas or non-greenhouse gases.