1.
The second most abundant element in Earth's crust. It is the principal component of sand and quartz and finds use in solar cells, computer chips, caulking materials, and abrasives.
Explanation
Silicon is the second most abundant element in the Earth's crust and is widely found in sand and quartz. It has various industrial applications, including its use in solar cells, computer chips, caulking materials, and abrasives. This explanation provides information about the properties and uses of silicon without explicitly stating that it is the correct answer.
2.
A metallic element that serves as the negative pole in the common flashlight battery. It is used to plate a protective film on iron objects (as in galvanized buckets). Melted with copper, it becomes brass .
Explanation
Zinc is a metallic element that is commonly used as the negative pole in flashlight batteries. It is also used to plate a protective film on iron objects, such as galvanized buckets. When zinc is melted with copper, it forms brass.
3.
A gaseous nonmetal, the most abundant element of Earth. It makes up some 21% of Earth's atmosphere and is essential to most forms of life.
Explanation
Oxygen is a gaseous nonmetal and the most abundant element on Earth. It constitutes approximately 21% of Earth's atmosphere and is crucial for sustaining life in most forms.
4.
This metal is the best conductor of heat and electricity. Its scarcity prevents it from common use for such purposes. It was used extensively in the past in the manufacture of coins, but has become too expensive. It is used today for fine eating utensils and decorative objects. Some of its compounds are sensitive enough to light to be used in photographic film.
Explanation
Silver is the best conductor of heat and electricity, making it ideal for use in various applications. However, its scarcity limits its common use for such purposes. In the past, silver was extensively used in coin manufacturing, but due to its high cost, it is no longer feasible. Today, silver is primarily used for fine eating utensils and decorative objects. Additionally, some of its compounds are light-sensitive, making them suitable for use in photographic film.
5.
The lightest and most abundant element; the fuel of the universe. It is believed that all other elements were originally formed from a series of stellar nuclear reactions beginning with this element. It is found in numerous compounds such as water and in most carbon-containing compounds.
Explanation
Hydrogen is the lightest and most abundant element in the universe. It is considered the fuel of the universe because it is believed that all other elements were formed from a series of nuclear reactions that began with hydrogen. Hydrogen is found in various compounds, including water and carbon-containing compounds.
6.
Nicknamed quicksilver, it is the only metallic element that is a liquid at room temperature. It is used in thermometers because it expands significantly and regularly when heated. Its high density makes it a practical substance to use in barometers. It is a toxic "heavy" metal.
Explanation
Mercury is the correct answer because it is the only metallic element that is a liquid at room temperature. It is commonly referred to as quicksilver due to its appearance. It is used in thermometers because it expands consistently and significantly when heated, allowing for accurate temperature measurements. Its high density makes it suitable for use in barometers, which measure atmospheric pressure. However, mercury is also a toxic heavy metal, which requires careful handling and disposal.
7.
The most abundant metal in Earth's crust, this silver-white element is characterized by its low density, resistance to corrosion, and high strength. It is used for a variety of structural purposes, such as in airplanes, boats, and cars.
Explanation
Aluminum is the correct answer because it is the most abundant metal in the Earth's crust. It is silver-white in color and has low density, high strength, and resistance to corrosion. These properties make it suitable for various structural purposes, including in airplanes, boats, and cars.
8.
A highly reactive, greenish-yellow gas used as a bleach and as a water disinfectant. It is a component of table salt.
Explanation
Chlorine is a highly reactive, greenish-yellow gas that is commonly used as a bleach and a water disinfectant. It is also a component of table salt.
9.
A metallic element that is used as a corrosion-resistant coating on the inside of cans used for packaging food, oil, and other substances.
Explanation
Tin is a metallic element that is commonly used as a corrosion-resistant coating on the inside of cans used for packaging food, oil, and other substances. It helps to prevent the can from rusting and keeps the contents safe and uncontaminated. Tin is known for its low toxicity and ability to form a protective layer, making it an ideal choice for food packaging.
10.
A gaseous nonmetal that makes up 78% of Earth's atmosphere. Its compounds are important components of proteins, fertilizers, and many explosives.
Explanation
Nitrogen is a gaseous nonmetal that makes up 78% of Earth's atmosphere. It is an essential element for life as its compounds are important components of proteins, fertilizers, and many explosives. Nitrogen is crucial for the growth and development of plants and is also used in the production of various industrial materials.
11.
A yellow, nonreactive, metallic element that has been highly valued since ancient times for its beauty and durability.
Explanation
Gold is a yellow, nonreactive, metallic element that has been highly valued since ancient times for its beauty and durability. It is known for its vibrant yellow color and its resistance to corrosion and tarnish. Gold has been used for centuries in jewelry and decorative arts due to its lustrous appearance. It is also a symbol of wealth and prosperity in many cultures. Additionally, gold is a good conductor of electricity and is used in various industries such as electronics and dentistry.
12.
A soft, highly reactive metal. Its compounds include table salt, lye, and baking soda.
Explanation
Sodium is a soft and highly reactive metal that forms compounds such as table salt, lye, and baking soda. Sodium is known for its reactivity and is commonly found in various compounds used in everyday life. Table salt, which is sodium chloride, is a common seasoning and preservative in food. Lye, also known as sodium hydroxide, is used in soap making and as a cleaning agent. Baking soda, or sodium bicarbonate, is used in baking and as a household cleaning agent. Therefore, sodium is the correct answer based on the description provided.
13.
This magnetic, metallic element is used extensively for structural purposes. It is the main ingredient in steel. This element is necessary for the human body to make hemoglobin, which carries oxygen in the blood.
Explanation
Iron is a magnetic, metallic element that is widely used for structural purposes. It is the main component of steel, which is used in construction, manufacturing, and various other industries. Additionally, iron is essential for the human body as it is a key component of hemoglobin, the protein responsible for carrying oxygen in the blood. Without iron, the body would not be able to transport oxygen efficiently, leading to various health issues. Therefore, iron is both important for industrial purposes and vital for human health.
14.
A reddish, lustrous, ductile, malleable metal that occurs in nature in both free and combined states. It forms the body of the Statue of Liberty. Other uses include electrical wiring, pennies, and decorative objects.
Explanation
Copper is a reddish metal that has a shiny appearance and can be easily shaped. It is found in nature in various forms and is commonly used in the construction of the Statue of Liberty. Copper is also widely used in electrical wiring due to its excellent conductivity. Additionally, it is used to make pennies and decorative objects.
15.
A red, highly reactive, fuming liquid with a foul smell. It finds limited use as a disinfectant.
Explanation
Bromine is a red, highly reactive, fuming liquid with a foul smell. It is known for its disinfectant properties, although its use is limited. This explanation accurately describes bromine based on its physical and chemical properties, as well as its limited application as a disinfectant.
16.
A yellow nonmetal that occurs in both free and combined states. It is used in making match tips, gunpowder and vulcanized rubber. Its presence in coal leads to acid rain
Explanation
Sulfur is a yellow nonmetal that can be found in both free and combined states. It is commonly used in the production of match tips, gunpowder, and vulcanized rubber. Additionally, sulfur is known to contribute to acid rain when it is present in coal.
17.
A soft, dense metal used in bullets and car batteries. It was once used extensively both in plumbing and in paints. Concern over its biological effects caused a ban on its use for these purposes. It is being phased out as a gasoline additive for the same reason.
Explanation
Lead is a soft and dense metal that has been widely used in bullets and car batteries. It was also commonly used in plumbing and paints, but due to concerns about its negative impact on health, its use for these purposes has been banned. Similarly, lead is being phased out as a gasoline additive because of its harmful effects.
18.
An unreactive, gaseous element used in advertising signs for the bright reddish-orange glow it produces when an electric current is passed through it.
Explanation
Neon is an unreactive, gaseous element that is commonly used in advertising signs because of the bright reddish-orange glow it produces when an electric current is passed through it. This unique property of neon makes it ideal for creating eye-catching and vibrant signs that can be easily seen from a distance.
19.
A highly reactive metal of low density. It is one of the three main elements found in fertilizer. Its compounds are quite similar to those of sodium, though typically more expensive.
Explanation
Potassium is a highly reactive metal with low density. It is commonly found in fertilizers as one of the three main elements. Its compounds resemble those of sodium but are usually more costly.
20.
A silver-white, lustrous, radioactive metal. Used as fuel in nuclear power plants and in atomic warheads.
Explanation
Uranium is a silver-white, lustrous, radioactive metal that is commonly used as fuel in nuclear power plants and in atomic warheads. It is highly valued for its ability to produce large amounts of energy through nuclear reactions. Due to its radioactive properties, uranium can undergo fission, releasing a tremendous amount of energy. This makes it a crucial component in the production of nuclear energy and weapons.
21.
A component of all living matter and fossil fuels; graphite and diamond are both composed of this, as well as soot.
Explanation
Carbon is a fundamental component of all living matter and fossil fuels. It is also found in graphite, diamond, and soot. This element is known for its ability to form a wide variety of compounds due to its unique bonding properties. Carbon's presence in living organisms and fossil fuels makes it an essential element for life and a significant contributor to the energy industry. Graphite and diamond, both composed of carbon, have distinct physical properties that make them valuable in various industries.
22.
One of the three magnetic elements, this metal is used in 5-cent pieces and other coins, in electroplating, and in nichrome wire.
Explanation
Nickel is one of the three magnetic elements, commonly used in various applications. It is used in the production of 5-cent pieces and other coins due to its durability and resistance to corrosion. Nickel is also used in electroplating processes to provide a protective coating on various surfaces. Additionally, it is a key component in the production of nichrome wire, which is used in heating elements and electrical resistors. Therefore, nickel fits the description provided in the question.
23.
A reactive, silver-white metal that is second in abundance to sodium in ocean water. Due to its low density and high strength, its alloys are often used for structural purposes in the transportation industry, as in "mag" wheels. It is also used in fireworks and incendiary bombs because it ignites readily. Some of its compounds, such as Epsom salt and milk of magnesia, have medicinal uses.
Explanation
Magnesium is a reactive, silver-white metal that is abundant in ocean water, second only to sodium. Its low density and high strength make it a popular choice for structural purposes in the transportation industry, such as in "mag" wheels. It is also known for its ability to ignite readily, which is why it is used in fireworks and incendiary bombs. Additionally, some compounds of magnesium, like Epsom salt and milk of magnesia, have medicinal uses.
24.
A solid purple-black nonmetal which changes to a deep purple gas upon heating. An alcohol solution of this element serves as an effective skin disinfectant. A compound of this element is added to sodium chloride to prevent goiter.
Explanation
Iodine is a solid purple-black nonmetal that sublimes into a deep purple gas when heated. It is commonly used as a skin disinfectant in the form of an alcohol solution. Additionally, iodine compounds are added to sodium chloride to prevent goiter, a condition caused by iodine deficiency.
25.
A widely distributed nonmetal never found it its free elemental state. It is an essential component in all cells, DNA, and various animal tissues and bones. It is also one of the three main elements in fertilizers.
Explanation
Phosphorus is a widely distributed nonmetal that is never found in its free elemental state. It is an essential component in all cells, DNA, and various animal tissues and bones. Additionally, phosphorus is one of the three main elements in fertilizers.
26.
A highly reactive metal. It is used in the manufacture of synthetic rubber and drugs. One of its compounds has been used to successfully treat a certain type of mental illness. It finds limited used in nuclear weapons. It is also used in long lasting batteries, such as in laptop computers.
Explanation
Lithium is a highly reactive metal that is used in the production of synthetic rubber and drugs. It has been found to be effective in treating a specific type of mental illness. Although it has limited use in nuclear weapons, it is more commonly used in long-lasting batteries, including those found in laptop computers.
27.
A reactive metal whose compounds make up limestone, chalk, cement, and the bones and teeth of animals. Milk is a good nutritional source of this element.
Explanation
Calcium is a reactive metal that is found in various compounds such as limestone, chalk, cement, and the bones and teeth of animals. It is also an essential nutrient for the human body and can be obtained from milk, making it a good nutritional source.
28.
A reactive, metallic element. Its compounds are used as a medical "cocktail" that patients drink to outline the stomach and intestines for X-ray examinations. Its compounds also give green colors to fireworks.
Explanation
Barium is a reactive, metallic element that is commonly used in medical procedures to outline the stomach and intestines for X-ray examinations. When barium compounds are ingested by patients, they provide a contrast that helps to highlight the digestive system in X-ray images. Additionally, barium compounds are known to produce green colors in fireworks, making them a popular choice for creating vibrant displays.
29.
A highly reactive, gaseous nonmetal. Its components are added to some toothpastes and many urban water supplies to prevent tooth decay.
Explanation
Fluorine is a highly reactive, gaseous nonmetal that is added to toothpastes and water supplies to prevent tooth decay. It is able to react with the enamel of teeth, forming a protective layer that helps to prevent the formation of cavities. Its reactivity also allows it to inhibit the growth of bacteria in the mouth, further contributing to its effectiveness in preventing tooth decay. Therefore, fluorine is commonly used in dental hygiene products and water fluoridation programs to promote oral health.
30.
An unreactive, gaseous element that is a product of the nuclear reaction (fusion) of hydrogen atoms. This reaction occurred at the beginning of time and occurs today in stars such as our sun. The second most abundant element in the universe, it is quite rare on Earth. Small concentrations are found in some natural gas deposits. It is used in blimps because of its low density. It is also used in cryogenic work because it can be compressed to a liquid that has a temperature of -269 degrees celsius.
Explanation
Helium is an unreactive, gaseous element that is produced through the nuclear fusion of hydrogen atoms. This fusion reaction took place during the early stages of the universe and continues to occur in stars like our sun. Although helium is the second most abundant element in the universe, it is relatively rare on Earth. However, small amounts can be found in certain natural gas deposits. Helium's low density makes it suitable for use in blimps, and it can also be compressed into a liquid form with a temperature as low as -269 degrees Celsius, making it useful in cryogenic applications.