sodium metal is insoluble in ether.

sodium metal dissolves in water to produce a gas.
The copper bottom on a frying pan turns black after several heatings.
Are these physical or chemical changes..

Sodium metal is insoluble in ether - No change but technically you can call the sodium in ether an insoluble mixture and therefore a physical change.

Sodium metal dissolves in water to produce a gas - You get a chemical change happening here because the sodium reacts with the water.

The copper bottom on a frying pan turns black after several heatings - That's a chemical reaction forming copper (II) oxide so it's a chemical change.

physical or chemical property

sodium metal fohrmhs an oxide when heated with oxygen?

The solubility of sodium metal in ether (a nonpolar solvent) is a physical change. When a substance dissolves in a solvent, it undergoes a physical change, as the individual particles of the substance separate and disperse throughout the solvent.

The dissolution of sodium metal in water to produce a gas (hydrogen gas) is a chemical change. In a chemical change, the composition and properties of a substance are altered, resulting in the formation of new substances.

The blackening of the copper bottom on a frying pan after several heatings is a chemical change. This blackening is likely due to the formation of a copper oxide layer on the surface of the copper. Chemical reactions occur between the copper and substances in the air (such as oxygen or moisture) at high temperatures, resulting in the formation of a new substance (copper oxide) with different properties.

To determine whether the given observations represent physical or chemical changes, we need to understand the characteristics of each type of change.

A physical change refers to a change in the physical properties of a substance without altering its chemical composition. The substance retains its identity even after undergoing a physical change. Examples include changes in state (solid, liquid, gas), changes in shape or size, and changes in physical properties such as melting, freezing, or dissolving.

A chemical change, on the other hand, refers to a process where one or more substances are transformed into new substances with different chemical properties. Chemical changes involve the breaking and forming of chemical bonds, resulting in the rearrangement of atoms and a change in the composition of the substance.

Let's examine each observation:

1. Sodium metal is insoluble in ether.
This observation represents a physical change because it describes the solubility of sodium metal in a particular solvent (ether). Solubility is a physical property and does not involve any chemical reactions or changes in the chemical composition of the sodium metal.

2. Sodium metal dissolves in water to produce a gas.
This observation represents a chemical change. When sodium metal dissolves in water, it undergoes a chemical reaction with the water molecules, producing hydrogen gas and aqueous sodium hydroxide. The reaction involves the exchange of atoms and the formation of new substances, indicating a chemical change.

3. The copper bottom on a frying pan turns black after several heatings.
This observation suggests a chemical change. When copper turns black after heating, it indicates the formation of a copper oxide layer on the surface. Copper reacting with oxygen in the air forms copper oxide, which has a black color. This transformation involves a chemical reaction between copper and oxygen, resulting in a change in the chemical composition of the copper and indicating a chemical change.

In summary:
- The solubility of sodium metal in ether is a physical change.
- The dissolution of sodium metal in water to produce a gas is a chemical change.
- The formation of a black copper oxide layer on a frying pan is a chemical change.