Physical Science- Unit In Matter

Flammability is a chemical reaction. When a substance is flammable, it means that it can undergo a chemical reaction called combustion, where it reacts with oxygen in the air to produce heat, light, and usually flames. This reaction involves the breaking and forming of chemical bonds in the substance, resulting in the release of energy. Flammability is a characteristic property of certain substances and is determined by their chemical composition and structure.

Color is not a form of matter because it is a visual perception that is created by the interaction of light with objects. It is not a physical substance or state of matter like solid, liquid, or gas. Color is subjective and can vary depending on the observer's perception and the lighting conditions.

Elements are the simplest form of matter and cannot be broken down into simpler substances. They are composed of tiny particles called atoms, which are the building blocks of all matter. Atoms combine together to form molecules and compounds, giving each element its unique properties and characteristics. Therefore, atoms are the fundamental units that make up elements.

The statement is true because matter can indeed be categorized into two main types: pure substances and mixtures. A pure substance is made up of only one type of particle and cannot be separated into other substances by physical means. On the other hand, a mixture is composed of two or more substances that are physically combined and can be separated through various methods. Therefore, matter can be classified into these two categories based on its composition.

The properties of color, shape, size, and sound are physical properties because they can be observed and measured without changing the chemical composition of the substance. These properties are inherent to the object and can be determined through visual or auditory perception. Reactivity, on the other hand, is a chemical property as it involves the substance's ability to undergo a chemical reaction or change in composition when exposed to certain conditions.

The statement in the question suggests that there are a certain number of types of chemical properties. The answer "two" indicates that there are only two types of chemical properties. This implies that chemical properties can be categorized into two distinct groups or classifications.

Air is not a form of a pure substance because it is a mixture of different gases such as nitrogen, oxygen, carbon dioxide, and others. A pure substance consists of only one type of substance with uniform properties throughout, whereas air is a combination of multiple gases with varying properties.