Energy : Capacity And Transfer Heat Essay

2. a) Liquid nitrogen boiling at -196°C is a physical property because it describes the boiling point of a substance, which is also when it changes state. A change of state, from a liquid to a gas, is a physical property because there is no new substance being created.

Every individual is different in a specific way. Like people, substances have unique qualities, such as properties, which aid chemists to differentiate and identify the particular components the substances consists of. These particular qualities are identified as either physical or chemical properties. Physical properties are properties which do not require a chemical change of its composition in order for the substance to be classified. A few examples of physical properties include color, density, odor, boiling point, melting

A physical change includes a change in the material without affecting its composition, such as the physical state change. However, a chemical change includes the change in the composition of the substance. The change in color, formation of a gas or a solid product, and the production of energy are the evidences of a chemical reaction, thus, of a chemical change.

The composition of a pure substance is constant, and thus pure substances have characteristic physical properties that do not change and this is why we are able to separate each element in this lab experiment. Examples of physical properties that can be used to describe pure substances include solubility, conductivity, magnetism, density, boiling point, and melting point.

Temperature: Measure of the average speed of molecules rather than the total amount of heat energy in matter.

Energy is the strength and ability that is required in order to perform physical or mental activities. There are different forms of energy these consist of: magnetic, kinetic, heat, light, gravitational, chemical, sound, electrical, elastic and nuclear.

Physical Properties: A property that can be observed or measured without changing the chemical identity of the substance.

Hypothesis: If we use these materials and use magnets, water, burners, and filters on the mixtures and elements given we should determine what kind of effect these materials given will have on these mixtures and elements, physical or chemical.

4. The following examples do not always indicate chemical change. For example, change in color will always indicate chemical change because the color changes but it does not change the substance’s physical properties. The apparent loss in mass is a phase change; therefore the entire substance goes through a physical change. The apparent disappearance of a substance is a chemical change and will always be a chemical change because it might result of a soluble substance dissolving in a liquid and changes the entire substance in a chemical phase.

Energy is a concept.� Most definitions of the word energy fail to provide its exact meaning when applied to scientific matters.� In science the word energy is a concept that expresses two measurable properties, heat and work.� Here is the relationship of energy, heat and work:

A chemical change is a change that alters the identity of a substance. A chemical change can be identified by five things: change in mass, formation of a precipitate, release of heat and/or light, color change, or giving off gas.

Physical changes can be seen through an altering of the substances physical property. A substances physical property is observed and measured without changing the composition of the subject. Descriptive words that would help to identify a substance’s physical property include hard, soft, brittle, flexible, heavy, and light just to name a few.

In a gas, the molecules have enough kinetic energy so that the effect of intermolecular forces is small (or zero for an ideal gas), and the typical distance between neighboring molecules is much greater than the molecular size. A gas has no definite shape or volume, but occupies the entire container in which it is confined.

Matter is defined as anything that occupies space and can be perceived by one or more senses; a physical body, a physical substance, or the universe as a whole. There are four distinct states of matter: solids, liquids, gases, and plasma. There are other states of matter such as Bose-Einstein condensates and neutron degenerate matter, but those states can only be found under extreme conditions.

Heat is a form of energy that is transferred between two substances at different temperatures. The flow of the energy is from the object of higher temperature to the object of lower temperature. The heat is measured in units of energy, usually calories or joules. Temperature on the other hand, is how cold or hot an object is. The temperature is the average kinetic energy per molecule of a substance. This is measured in degrees on the Celsius or Fahrenheit or in Kelvins.