Questions and Answers
What can you conclude about the classification of boron?
Boron is classified as a metalloid.
The very reactive nonmetals fluorine, chlorine, bromine, iodine, and astatine are in the group called ________.
halogens
The electrons in the outer shell of an atom are called the ________ electrons.
valence
What can you conclude about the classification of silicon?
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Halogens are _______ conductors and have __________ melting and boiling points.
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All of the noble gases have ____________ electrons in their outer shell.
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Which of the following make up most of the earth and its organisms?
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What can you conclude about the classification of krypton?
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What is the largest number of electrons that can be in an electron shell?
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Hydrogen is an example of a ______________.
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What is the element that is a part of the nonmetals classification but is not organized to be around it in the Periodic table?
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___________ is essential to respiration which is the process that gives your cells energy.
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How many of the known elements are considered essential for good health?
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The necessary element that forms part of the structure of DNA and RNA is ___________.
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_________ in the body is locked up in the water which is 70% of the body.
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We get most of the sodium and chlorine we need from the ______________ we eat.
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___________ strengthens teeth and bones.
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Match the following elements with their best descriptions:
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Study Notes
Classification of Elements
- Boron is a metalloid possessing characteristics of both metals and non-metals, and it appears dull yet exhibits ductility.
- Silicon, another metalloid, is a poor conductor of heat and electricity, indicating its mixed properties.
Halogens
- Halogens include highly reactive nonmetals: fluorine, chlorine, bromine, iodine, and astatine.
- Halogens are characterized by poor conductivity and low melting and boiling points.
Atomic Structure
- Valence electrons refer to the electrons located in the outermost shell of an atom.
- Noble gases, categorized under group 18, possess a full valence shell containing eight electrons, making them non-reactive.
Composition of Earth
- Non-metals constitute the majority of Earth's composition and are vital for the organisms inhabiting the planet.
- Hydrogen is categorized as a non-metal, yet it is positioned separately on the Periodic Table.
Essential Elements for Health
- A total of 25 known elements are deemed essential for maintaining good health.
- Oxygen is crucial for respiration, which provides energy to cells.
Role of Key Elements
- Phosphorus is integral to the DNA and RNA structures, highlighting its biological significance.
- Calcium strengthens teeth and bones, showcasing its importance in human health.
- Nitrogen is essential for the synthesis of amino acids, which are building blocks of proteins.
Sodium and Chlorine Sources
- Most sodium and chlorine intake derives from dietary salt, underlining its role in nutrition.
- Approximately 70% of the hydrogen in the human body is contained in water, emphasizing its abundance and necessity for life.
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Description
Test your knowledge with these flashcards from Science Week 9.30! This quiz covers essential terms and definitions related to chemistry, including metalloids and halogens. Challenge your understanding of valence electrons and their significance in atomic structure.
