Questions and Answers
There are ___ unique substances (elements).
118
All the gold ever mined would fit into a single cube about __ feet on one side.
60
Three-quarters of the elements are ___.
metals
How an atom chemically reacts depends on how willing it is to share ___.
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How much would a 60 pound block of gold be worth in dollars?
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List two things copper is used for.
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When copper is combined with another element, ___, it makes bronze, the first man-made metal alloy.
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The number of ___ determines what kind of element the atom is.
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The number of protons is called the atomic ___ and it's the fundamental organizing principle of every table of the elements.
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Metals are shiny, malleable materials that conduct ___.
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Most people think of ___ as white and chalky, but it's actually a silver, shiny metal.
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Old bowls get their orange color from ___, and it's actually dangerously radioactive.
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The table organizes the elements by atomic number, yet the creator of the periodic table, ___ ___, knew nothing about protons or atomic numbers.
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The group that fits neatly onto the end of the table, the ___ ___, are unwilling to mix with other elements, to react with them.
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Protons may determine the identity of an element, but ___ rule its reactivity.
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An atom with ___ electrons in its outer shell makes one happy, satisfied atom.
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The column just before the stable noble gases are called the ___. They have an outer shell that needs just one more electron to be full.
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The ___ metals are the first column. Each of them has full shells, plus one electron sitting in a new outer shell.
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The ion chromatograph looks for positively or negatively charged molecules, called ___, in the residue, fragments of the original chemical explosive.
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Every time atoms form a new bond, the reaction releases ___.
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How do you speed up a fire to create an explosion? You regulate the amount of ___ and how closely it's packed together with other elements.
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The oxygen that powers all those explosions makes up ___% of our atmosphere; it's the most abundant element in the earth's crust.
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What six elements make life possible?
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List two ways that carbon is found in its pure form.
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Your body composition is about ___% carbon and ___% nitrogen.
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Hydrogen and oxygen can actually be separated from water using a little bit of ___.
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In a person's body, there's about ___% oxygen.
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Phosphorus is actually involved in something really important called ___, which is the molecule that all cells use for energy.
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Phosphorus makes up about ___% of the human body; it was the first element isolated from a living creature.
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Altogether just those six CHNOPS elements make up 97% of the weight of a body, but what about the other 3%? Those are what's called the ___ elements.
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__ is important for energy metabolism.
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__ is an important part of nervous system function.
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In total, the human body uses more than ___ elements in ways and quantities that are unique to us.
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As the planet cooled, another ancient microorganism evolved and changed everything. They are called cyanobacteria, but we know them all - ___. They found a way to get their energy from light and water, releasing oxygen as a byproduct, just like modern plants do.
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Around 90% of all atoms in the universe are ___, and they were all made by the Big Bang, more than 13 billion years ago.
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Stars like our own sun are constantly turning hydrogen atoms into element number two: helium. It's a process called ___.
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By the time it's fusing iron, a star is in its death throes. It begins to collapse, and if it's massive enough, that collapse leads to a powerful explosion called a ___.
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This element, with 14 protons and 14 electrons, is the second most abundant element in the earth's rocky crust and is a member of one of the smallest neighborhoods on the table: the semiconductors: ___.
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Glass starts with ordinary ___, which is made of a combination of silicon and oxygen.
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Glassmakers have learned how to precisely place minute amounts of ___ atoms.
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High tech pieces are made of the ___ ___, 15 elements located near the bottom of the table.
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List three uses of the rare earth metal neodymium.
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Where do the majority (98%) of rare earth minerals come from in the world?
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__ makes magnets, but by adding neodymium makes magnets on steroids.
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They accidentally discovered that the strong neodymium magnets (and other rare earth elements) can actually repel ___.
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Elements come in more than one version. The different versions are called ___. The difference between them is the number of neutrons in the nucleus.
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To determine how long ago droughts occurred, Scott used - to date the trees because it is unstable and the atoms begin to deteriorate over time in a process called radioactive decay.
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Carbon-14 can be used to date samples up to ___ years old.
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At the bottom of the periodic table, beginning with number 84, polonium, all the other elements and their isotopes are ___.
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Before the nuclear age, uranium was thought to be the end of the periodic table, but in the last 70 years, scientists have left nature behind and created ___ new elements.
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Study Notes
Elements Overview
- There are 118 unique elements in total.
- Three-quarters of the elements are metals, known for their shiny and malleable properties.
Gold and Copper
- All gold ever mined can fit in a cube measuring 60 feet on each side, highlighting its rarity.
- A 60-pound block of gold is valued at approximately $1.5 million.
- Copper is utilized in electronics and building infrastructures; when combined with tin, it creates bronze.
Atomic Structure
- Chemical reactions of an atom depend on its willingness to share electrons.
- The identity of an element is defined by the number of protons in its nucleus, known as the atomic number.
- Electrons influence the reactivity of elements, despite protons determining their identity.
Group Properties
- The noble gases group, located at the end of the periodic table, is characterized by reluctance to react with other elements.
- Halogens, positioned before noble gases, have an outer shell needing just one more electron to be stable.
- Alkali metals constitute the first column of the periodic table, possessing full shells plus one additional electron.
Energy and Reactions
- Atom bond formation releases energy.
- Regulating oxygen concentration can expedite combustion for explosive reactions.
- Oxygen makes up 21% of the atmosphere and is the most abundant element in the earth's crust.
Life-Sustaining Elements
- CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur) are essential for life, composing 97% of body weight.
- Carbon is found in pure forms as diamond or graphite; in the human body, it constitutes about 18%.
- Phosphorus is crucial for ATP, the energy molecule for cells, comprising 1% of body composition.
Hydrogen and the Universe
- Hydrogen accounts for 90% of all atoms, formed during the Big Bang.
- Fusion processes in stars convert hydrogen to helium, leading to their lifecycle stages.
Elements in Earth and Technology
- Silicon, with 14 protons, is the second most abundant element in the earth's crust and is essential for semiconductors.
- Glass is produced from sand, which consists of silicon and oxygen, with precise metal atom placement enhancing its properties.
- Rare earth elements, particularly neodymium, are vital for high-tech applications in devices like computers and magnets.
Isotope and Radioactivity
- Isotopes are variations of elements distinguished by neutron count.
- Carbon-14 is used for dating samples up to 40,000 years old, based on its radioactive decay.
- Elements beyond polonium (atomic number 84) are all radioactive, and in 70 years, 26 new elements have been artificially created since the nuclear age.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on the unique substances that make up our universe with this quiz inspired by the NOVA episode 'Hunting the Elements'. From understanding the properties of metals to the role of electrons in chemical reactions, challenge yourself to remember fascinating facts about elements.
