Question

property cannot be observed until the metal and water react, and both the metal and the water change in the process.
in a chemical change, the particles of a substance are rearranged, resulting in a change in chemical composition. the substances undergoing the change are the reactants; the new substances formed are the products. when sodium reacts with water, sodium and water are reactants. sodium hydroxide and hydrogen gas are products.
analyze determine whether each observation describes a chemical or a physical property.
chemical physical
when a piece of sodium metal is placed in a test tube with water, the sodium fizzes and bubbles of a gas are produced. ____________
when table salt is added to water in a test tube, the table salt dissolves. ____________
when water is placed in a freezer at 0°c it becomes ice. ____________
when an iron bicycle is left outdoors and is exposed to moist air, it gets rusty. ____________
when a glass marble is heated and then quickly cooled, it shatters. ____________
extensive and intensive properties
scientists describe properties of matter as extensive and intensive. an extensive property is one that depends directly on the amount of a substance present. an intensive property is one that does not depend on the amount of the substance present. all quantities of a substance have the same values of the intensive property.
if you immerse a 12 - ounce can of regular cola and an equal - sized can of diet cola in a tub of water, you will notice that the regular cola sinks and the diet cola floats, although both cans contain the same volume. the sweetener in diet cola is hundreds of times sweeter per unit volume than the sugar in regular cola. so, a much smaller mass of sweetener is needed in the diet cola to produce the amount of sweetness sugar produces in regular cola.
explain what are the extensive and intensive properties described in this experiment? which properties would change and which would stay the same if you ran the experiment using 7.5 - ounce cans instead of 12 - ounce cans?
the mass changes and the density stays the same

Explanation:

• Chemical or Physical Property:
• Sodium reacting with water to produce gas involves a chemical change (new substances formed), so it's a chemical property.
• Table salt dissolving in water is a physical change (no new substance chemically formed), so it's a physical property.
• Water freezing to ice is a physical change (change of state, no new chemical substance), so it's a physical property.
• Iron rusting is a chemical change (iron reacts with oxygen and moisture to form iron oxide), so it's a chemical property.
• Glass marble shattering is a physical change (no new chemical substance, just change in physical form), so it's a physical property.
• Extensive and Intensive Properties:
• In the cola experiment, mass is an extensive property (depends on the amount of substance - a 12 - ounce can has more mass than a 7.5 - ounce can).
• Density is an intensive property (for a given substance, it doesn't depend on the amount. Diet cola has a lower density than regular cola regardless of the can size). If we use 7.5 - ounce cans instead of 12 - ounce cans:
• Mass (an extensive property) would change (be less for 7.5 - ounce cans compared to 12 - ounce cans).
• Density (an intensive property) would stay the same for regular cola and diet cola respectively (as it's a characteristic property of the substance mixture in each cola type).

Answer:

• Chemical or Physical Property:
• Sodium reacting with water: chemical.
• Table salt dissolving: physical.
• Water freezing: physical.
• Iron rusting: chemical.
• Glass marble shattering: physical.
• Extensive and Intensive Properties:
• Extensive property: mass. Intensive property: density.
• If using 7.5 - ounce cans: mass (extensive property) changes; density (intensive property) stays the same.