Site Loader

1. 1
•The end of scientific discipline is to look into and understand the natural universe. to explicate events in the natural universe. and to utilize those accounts to do utile anticipation •Scientific believing normally begins with observation. the procedure of garnering information about events or procedures in a careful -observation by and large involves utilizing the senses esp. hearing & A ; sight -the information gathered from observations is called informations.

•Quantitative day of the month expressed as figure
-Qualitative informations are descriptive and affect features •After observations. the research workers will suggest one or more hypotheses. •A hypothesis- is a proposed scientific account for a set of observation -some hypotheses are tested by garnering more informations

1. 2
•Spontaneous generation- hypothesis saying that life could originate from nonliving affair •Whenever possible. a hypothesis should be tested by an experiment in which merely one variable is changed at a clip. All other variables should be kept unchanged. or controlled. •Controlled experiment-a trial of the consequence of a individual variable by altering it while maintaining all other variables the same. •Manipulated variable- factor in an experiment that a scientist intentionally alterations ( INDEPENDENT VARIABLE ) •Responding variable- factor in an experiment that a scientist wants to detect. which may alter in response to the manipulated variable ( DEPENDENT VARIABLE ) •Theory- well-tested account that unifies a wide scope of observation 1. 3

•Living things portion some characteristic
-living things are made up of units called cells
-living things reproduce
-living things are based on a cosmopolitan familial codification
-living things grow and develop
-living things obtain and utilize stuffs and energy
-living things respond to their environment
-living things maintain a stable internal environment
-taken as a group. living things change over clip
•Some of the degrees at which life can be studied include molecules. cells. beings. populations of a individual sort of being. communities of different beings in an country. and the biosphere. At all these degrees. smaller life systems are found within larger system •Levels of Organization








-Biosphere ( largest & A ; most complex )
-Ecosystem
-Community
-Population
-Organism
-Groups of Cells
-Cells
-Molecules ( smallest. that make up living things )






1. 4
•Most scientists use the metric system when roll uping informations and executing experiments •Metric system- a denary system of measuring whose units are based on certain physical criterions & A ; are scaled on multiples of 10 •Microscopes are devices that produce exaggerated images of constructions that are excessively little to see with the unaided eyes •Light microscopes produce magnified images by concentrating seeable light beams. Electron microscopes produce magnified images by concentrating beams of negatrons. -most normally used microscope

•Compound light microscopes – allow visible radiation to go through through the specimen and utilize two lenses to organize an image. •Electron microscope- usage beams of negatrons. instead than visible radiation. to bring forth images. •Transmission electron microscope ( TEMs ) shine a beam of negatrons through a thin specimen. •Scanning negatron microscopes ( SEMs ) scan a narrow beam of negatrons back and Forth across the surface of a specimen.

2. 1
•Most elements are found combined with other elements in compound. •A chemical compound is a substance formed by the chemical combination of two or more elements in definite proportions. •The chief types of chemical bonds are ionic bonds and covalent bonds •An ionic is formed when one or more negatrons are transferred from one atom to another -an atom that loses negatrons has a positive charge.

-an atom that additions negatrons has a negative charge
•These positively and negatively charged atoms are known as ions •A covalent bond- signifiers when negatrons are shared between atoms. -when the atoms portion two negatrons. the bond is called a individual covalent bond •When atoms are joined together by covalent bonds is called molecule •The molecule is the smallest unit of most compounds

2. 2
•Water is impersonal. It is polar. Water is non ever pure it is frequently found as portion of a mixture. •A H2O molecule is polar because there is an uneven distribution of negatrons between the O and H atoms •The attractive force between the H atom on one H2O molecule & A ; the O atom on another H2O molecule is an ex: of a H bond •Cohesion- is an attractive force between molecules of the same substance -water is highly cohesive

•Adhesion- is an attractive force between molecule of different substances •Mixture- is a stuff composed of two or more elements or compounds that are physically assorted together but non chemically combined •All of the constituents of a solution are equally distributed throughout the solution •Solute the substance that is dissolved ex: Table salt

•Solvent- the substance in which the solute dissolve. Ex-husband: Water •Suspension- mixture of H2O and nondissolved stuff
•Chemists devised a measuring system called pH graduated table to bespeak the concentration of H+ ions in solution
-0 to 6/6. 5 is acidic
-7 is impersonal
-7. 5/8 to 14 is basic



Post Author: admin