. Using the key choices, complete the crossword puzzle by answering each of the clues provided. Key Choices Atom Element Ion Molecule Protons Electrons Energy Matter Neutrons Valence Across 4. The smallest particle of an element that retains the properties of the element. 7. Formed when atoms combine chemically. 8. Uncharged subatomic particles, forming part of an atom. 9. Subatomic particles that determine an atom’s chemical behavior or Down 1. A unique substance composed of atoms having the same atomic number. 2. Name given to the electron shell that contains the most reactive electrons. 3. Positively charged particles forming part of an atom. 5. Anything that takes up space and has mass (weight). 6. An electrically charged atom or group of atoms. 9. The ability to do work.
The Correct Answer and Explanation is:
Across
4. Atom — The smallest particle of an element that retains the properties of the element.
7. Molecule — Formed when atoms combine chemically.
8. Neutrons — Uncharged subatomic particles, forming part of an atom.
9. Valence — Subatomic particles that determine an atom’s chemical behavior or bonding.
Down
- Element — A unique substance composed of atoms having the same atomic number.
- Valence — Name given to the electron shell that contains the most reactive electrons.
- Protons — Positively charged particles forming part of an atom.
- Matter — Anything that takes up space and has mass (weight).
- Ion — An electrically charged atom or group of atoms.
- Energy — The ability to do work.
Explanation
The fundamental building block of matter is the atom (Across 4), which is the smallest particle of an element that retains the chemical properties of that element. Atoms themselves are composed of subatomic particles including protons (Down 3), which are positively charged and define the element’s identity by their number (the atomic number), neutrons (Across 8), which have no charge and contribute to the atom’s mass, and electrons, which orbit the nucleus and have a negative charge (though “electrons” wasn’t used explicitly in the puzzle, their shell is referenced).
An element (Down 1) is a pure substance made up of only one kind of atom, characterized by its unique number of protons. These atoms can combine chemically to form a molecule (Across 7), which is the smallest unit of a compound that retains its chemical properties.
The valence (Across 9 and Down 2) refers to the outermost electron shell or the electrons in that shell that determine how an atom interacts chemically with others. Valence electrons are crucial because they participate in bonding, which affects the chemical behavior of the atom.
Matter (Down 5) is anything that has mass and occupies space, and all substances including atoms and molecules are forms of matter. When atoms gain or lose electrons, they become charged particles called ions (Down 6).
Lastly, energy (Down 9) is the capacity to do work, an essential concept in physics and chemistry because energy changes often accompany chemical reactions and physical changes in matter.
This crossword integrates key concepts from atomic theory and chemistry, reinforcing understanding of the fundamental nature of matter and chemical interactions.
