why do we need to be careful about what we du
Why Do We Need To Be Careful About What We Dump In The ...
Physical conditions like temperature and pressure affect state of matter. … When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid (melting), liquid to gas (vaporization), or solid to gas (sublimation).
The characteristic of the material before placing it in the water is of course dry because once you place it in the water it becomes wet. the correct sick of each material before placing them on water is dry because water will make them wet . when you squeeze each material the water will come out .
Chemical changes occur when bonds are broken and/or formed between molecules or atoms. This means that one substance with a certain set of properties (such as melting point, color, taste, etc) is turned into a different substance with different properties.
A color change, formation of a precipitate or a gas, or temperature changes are the evidences of a chemical reaction.
During a chemical change, the composition of matter always changes. Four possible clues to chemical change include a transfer of energy, a change in color, the production of a gas, or the formation of a precipitate. During any chemical reaction, the mass of the products is always equal to the mass of the reactants.
In order for a chemical reaction to take place, the reactants must collide. The collision between the molecules in a chemical reaction provides the kinetic energy needed to break the necessary bonds so that new bonds can be formed.
A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.
Change in Temperature. Change in Color. Noticeable Odor (after reaction has begun) Formation of a Precipitate.
A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible. The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass.
Characteristics of Chemical reaction
An acid will react with a metal to form a salt and hydrogen gas. The general word equation for the reaction between an acid and a metal is as follows: acid + metal → salt + hydrogen.