I would say Salt (NaCI), considering Beryllium, Tungsten, and Silver are all single elements and Salt is a combination of two elements, forming a compound known as sodium chloride.
- Salt (NaCI) - Chemically, table salt consists of two elements, sodium (Na) and chloride (Cl). Neither element occurs separately and free in nature, but are found bound together as the compound sodium chloride.
- Beryllium (Be) - A toxic bivalent element, steel gray, strong, light-weight, primarily used as hardening agent in alloys. Beryllium has one of the highest melting points of the light metals.
- Tungsten (W) - Also called wolfram, a chemical element, an exceptionally strong refractory metal of Group 6 (VIb) of the periodic Table, used in steels to increase hardness and strength and in lamp filaments.
- Silver (Ag) - A chemical element with symbol Ag and atomic number 47. Classified as a transition metal, Silver is a solid at room temperature.
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Hope this helps!