Meaning
The kanji 溶 (よう) expresses the core concepts of "dissolving," "melting," and "fusing." It's a fundamental character used to describe changes in states of matter and various physical and chemical processes. Essentially, 溶 signifies a transformation where a solid turns into a liquid, or one substance becomes uniformly incorporated into another liquid, seemingly disappearing or blending completely.
Its etymology offers a clear insight into its meaning. The character 溶 is a phono-semantic compound, meaning it combines a semantic component (radical) that suggests its general category of meaning with a phonetic component that suggests its pronunciation. The radical on the left, 水 (みず・さんずい), meaning "water," clearly indicates that the kanji's meaning is related to liquids or processes involving them.
The right side, 容 (よう), serves as the phonetic component, giving the kanji its On'yomi reading of ヨウ. It also subtly contributes to the meaning. 容 itself means "contain," "form," or "appearance." Thus, when water (水) interacts with something, changing its form or appearance by containing it or absorbing it, the idea of "dissolving" or "melting" emerges. It visually represents something losing its original form and being absorbed into a liquid medium or transforming into a liquid state.
This kanji has 13 strokes and is classified as a Jōyō kanji, typically learned in secondary school (equivalent to Grade 9 in terms of complexity and usage, though not specifically assigned to a single grade like elementary school kanji).
Readings
On'yomi (音読み) — Chinese-derived readings
The primary On'yomi reading for 溶 is ヨウ (yō). This reading is often found in compound words, particularly those with a more technical, scientific, or formal nuance, describing processes or states related to dissolution or melting.
- 溶解 (yōkai) — dissolution, melting. This term is widely used in scientific contexts to describe a solid dissolving into a liquid, or a substance turning molten.
Example: 塩は水に溶解する。
Example: 熱で金属が溶解した。
- 溶液 (yōeki) — solution. This refers to a homogeneous mixture composed of one or more substances (solutes) dissolved in another substance (solvent).
Example: この試験管には透明な溶液が入っている。
Example: 砂糖水は水と砂糖の溶液だ。
- 溶接 (yōsetsu) — welding. This is the process of joining materials, typically metals, by causing coalescence, usually by heating them to their melting point and allowing them to fuse.
Example: 鉄骨を溶接してビルを建てる。
Example: 熟練した技術者が溶接を行った。
Kun'yomi (訓読み) — Native Japanese readings
Kun'yomi readings are deeply rooted in native Japanese vocabulary. They are used when the kanji is part of a verb or adjective, often accompanied by okurigana (送り仮名). For 溶, the main Kun'yomi readings are と-ける (to-keru), と-かす (to-kasu), and と-く (to-ku).
- 溶ける (tokeru) — This is an intransitive verb meaning "to melt," "to dissolve," or "to thaw." It describes something undergoing the process naturally or without a direct agent.
Example: 氷が溶ける。
Example: 雪が溶け始める。
Example: 砂糖が水に溶ける。
- 溶かす (tokasu) — This is a transitive verb meaning "to melt," "to dissolve," or "to liquefy (something)." It implies an agent actively causing the melting or dissolving.
Example: チョコレートを湯で溶かす。
Example: 薬を水に溶かす。
Example: バターを鍋で溶かす。
- 溶く (toku) — While とく can mean "to dissolve" or "to melt" in certain contexts (often implying stirring to mix or thin out a substance), its most common direct application for 溶 is in compounds like 溶き卵. Here, とく means to beat or whisk, making the egg homogenous, which is akin to dissolving its distinct parts.
Example: 夕食に溶き卵スープを作った。
Example: 味噌汁に溶き卵を入れる。
Common Words & Compounds
The kanji 溶 appears in a wide array of words and compounds, spanning scientific, industrial, and everyday contexts. Exploring these combinations helps clarify its various nuances.
Chemical and Material Processes
- 溶解度 (yōkaido) — solubility. The maximum amount of a substance that can be dissolved in a given amount of solvent at a specific temperature.
- 溶剤 (yōzai) — solvent. A substance, typically a liquid, capable of dissolving other substances (solutes).
- 溶媒 (yōbai) — solvent. Similar to 溶剤, this term is often used in more scientific or technical contexts.
- 溶質 (yōshitsu) — solute. The substance that is dissolved in a solvent to form a solution.
- 不溶性 (fuyōsei) — insolubility; insoluble. The property of not being able to dissolve in a particular solvent.
- 溶融 (yōyū) — melting; fusion. A more formal or technical term for the process of melting, often used for metals, rocks, or other high-temperature substances.
Actions and States
- 溶け込む (tokekomu) — to blend in; to melt into; to become assimilated. This can be used literally for substances or figuratively for people adjusting to a new environment.
- 溶岩 (yōgan) — lava; molten rock. This is a direct application of the concept of "molten" to rock that has erupted from a volcano.
- 溶血 (yōketsu) — hemolysis. The breakdown or destruction of red blood cells, which releases hemoglobin into the surrounding fluid.
- 融け合う (tokeau) — to merge; to blend; to melt together. This emphasizes a mutual blending or integration.
Industrial and Everyday Use
- ガス溶接 (gasu yōsetsu) — gas welding. A specific type of welding technique that uses a fuel gas and oxygen to heat and join metals.
- 溶け残る (toke nokoru) — to remain undissolved; to remain unmelted. Describes a portion of a substance that has not fully undergone the melting or dissolving process.
Example Sentences
氷が暖かい部屋でゆっくりと溶けています。
Kōri ga atatakai heya de yukkuri to toketeimasu.
The ice is slowly melting in the warm room.
砂糖をコーヒーに入れてよく溶かしてください。
Satō o kōhī ni irete yoku tokashite kudasai.
Please put sugar in your coffee and dissolve it well.
新しい職場に無事溶け込めるか心配です。
Atarashii shokuba ni buji tokekomeru ka shinpai desu.
I'm worried if I can successfully blend into the new workplace.
火山から溶岩が流れ出ています。
Kazan kara yōgan ga nagare deteimasu.
Lava is flowing out from the volcano.
薬は水に溶けやすい性質を持っています。
Kusuri wa mizu ni tokeyasui seishitsu o motteimasu.
This medicine has the characteristic of dissolving easily in water.
高温で金属を溶接する作業には危険が伴います。
Kōon de kinzoku o yōsetsu suru sagyō ni wa kiken ga tomonaimasu.
Welding metal at high temperatures involves risks.
彼の疲労は温かいお風呂に入ると溶けるように軽くなりました。
Kare no hirō wa atatakai ofuro ni hairu to tokeru yō ni karuku narimashita.
His fatigue lightened as if melting away after taking a warm bath.
この液体はあらゆる物質を溶解する力を持っています。
Kono ekitai wa arayuru busshitsu o yōkai suru chikara o motteimasu.
This liquid has the power to dissolve all substances.
味噌汁に溶き卵を入れると、まろやかな味になります。
Misoshiru ni tokitamago o ireru to, maroyaka na aji ni narimasu.
If you add beaten egg to miso soup, it will have a mild flavor.
Memory Tip
To remember 溶, focus on its two main components. The left part is the "water" radical (水, sometimes written as 氵). This immediately suggests that the kanji has something to do with liquids or processes involving water. The right part, 容 (ヨウ), means "contain" or "appearance."
Imagine dropping a sugar cube into a glass of water. The water (水) 'contains' the sugar, and the sugar's 'appearance' changes as it dissolves. It seems to melt away into the water, contained within it, losing its solid form. So, you can think: "water" + "contain/appearance" = "dissolve/melt." This visual helps connect the components to the kanji's core meaning.