What are elementary substances and how do they differ from
Feb 7, 2025 · What rule do you use to identify substance as elements and compounds? Elements are substances composed of only one type of atom, while compounds are substances …
What substances contain barium? - Answers
Feb 7, 2025 · Elements do not contain polyatomic ions. Examples of substances that do not contain polyatomic ions include water (H2O), sodium chloride (NaCl), and oxygen gas (O2).
Is the properties of a compound are usually the same as the
Feb 9, 2025 · For example, the melting point, boiling point, and density of a compound can be different from those of the individual elements in it.
What are trivalent and pentavalent impurities? - Answers
Dec 1, 2024 · The term impurity is used to describe the doping elements. Two element types are used for doping: trivalent and pentavalent.
What is the number of valence electrons for the elements in
Jun 4, 2024 · The group number indicates the number of valence electrons. For example, elements in group 1 have 1 valence electron, elements in group 2 have 2 valence electrons, …
Why is helium placed in group 8 if it has two valence electrons?
Jun 29, 2024 · For example, elements in group 1 have 1 valence electron, while elements in group 18 have 8 valence electrons (except for helium, which has 2).
List of inert gases? - Answers
May 20, 2024 · Scientists have observed that certain conditions can cause inert gases like xenon, krypton, and argon to form compounds with other elements.
What elements has properties similar to potassium? - Answers
Jun 9, 2024 · Any element in the alkali metal group would have similar chemical properties, for example they all react easily to water.
Why is hydrogen written alone on the periodic table? - Answers
May 26, 2024 · Hydrogen is not exactly written alone on the Periodic Table. The table is organized into rows and columns, both of which represent groupings of elements for different reasons. …
Why do some elements have names and symbol that do not …
Jun 8, 2024 · The periodic table lists the elements by their names and atomic symbols. For example, hydrogen is represented by the symbol H, and carbon is represented by the symbol C.