Domain 1 : Physical Science Flashcards
Solids
Characterized by their ability to retain their shape. relatively in-compressible. Melt when heated, and vaporize only slightly. All substances become solid if cooled sufficiently. EX: rock, crystals, wood, feather, ice
Liquids
Take the shape of their containers. Volume is consistent unless evaporation occurs. Intermediate state between solid and gas. EX: water, oil, milk honey
Gases
Expand to fill space. A compressible fluid, volume determined by pressure, temperature, and environment. EX: Air, helium, steam.
Mass
The amount of matter in a chemical substance. Commonly confused with weight.
Density
Determined by dividing mass over volume.
Hardness
Refers to various properties of matter in the solid phase that give it a high resistance to its shape changing when force is applied.
Scratch hardness: Resistance to fracture or permanent deformation.
Indentation hardness: Resistance to permanent deformation due to a constant load of a sharp object.
Rebound hardness: height of the bounce of an object dropped on the material, related to elasticity.
Mohs’ scale of hardness
rate minerals and put them on a scale from 1 to 10. 1 what is the softest and 10 is the hardest, determined by the ability of a harder mineral to scratch a softer mineral. for example talk is at one and a diamond is at 10.
Physical properties
Are the characteristics that make up the physical composition of a substance. Physical properties include color, form, conductivity, and density.
Physical changes
Don’t involve one substance changing into another. Water for example can change from a gas (water vapor) to liquid (water) to a solid (ice) I but the water molecules do not change. The particular state of water is determined by pressure and temperature.
Chemical changes
Occurring substances changed into something else. I chemical change occurs whenever compounds are formed or decompose. During this reaction there there is a rearrangement of Adams that make or break chemical bonds.
Chemical reactions
Show the number of molecules are formula units of the right reactants and products. For example, nitrous oxide is a colorless odorless gas that causes mild hysteria when inhaled, hence the name laughing gas you need: it is prepared by heating ammonium nitrate crystals.
Atoms
Made up of several tiny parts. At the center Atom is a core called the nucleus. the nucleus is made of particles called protons and neutrons. protons have a positive electrical charge, and neutrons have no charge. electrons move around the nucleus and electron clouds. electrons have a negative charge, and they are attracted to the positively charged protons and you and nucleus. this attraction keeps electrons in orbit around the nucleus
Chemical elements
Composed of only one atom and cannot be separated into different substances except in some instances by radioactive decay, or by nuclear reactions. the elements are assigned atomic numbers equal to the number of protons in the nucleus of their atoms.
Compounds
Are formed by the chemical combination of two or more elements and a fixed ratio. Water, for example, is made of molecules with the composition H2 O structure.
PH
A measure of acidity are basicity of a solution. The pH scale is not an absolute scale; it is relative to a set of standard solutions his pHs established by international agreement. Your water is said to be neutral. The pH for pure water at 25°C is close to seven. when foreign substances are dissolved in water and creates a solution. Solutions with the pH of less than seven are said to be acidic, and solutions with a pH greater than seven are said to be basic or alkaline. PH measurements are important for medicine, biology, chemistry, food science, environmental science, oceanography, and many other applications.
Litmus
A water-soluble mixture of different dyes extracted from linchpins. Is often absorbed going onto filter paper. The resulting piece of paper or solution with water becomes a pH indicator, Used to test Jerial’s birthday. Blue paper turns red under acidic conditions. Read paper turns blue under basic condition.
Mixture
A substance made by combining two or more different materials without a chemical reaction occurs. The product of a mechanical blending or mixing of chemical substances. Each ingredient retains its own chemical properties and makeup. Salt-and-pepper is a mixture.
Motion
Means that there is a constant change and the location of the body, And is described by stating objects position, velocity, and acceleration