Chapter 16 Elements of Chemistry The Big Idea
Chapter 16 Elements of Chemistry The Big Idea: Atoms are the fundamental building blocks of everything around us
16. 1 Chemistry: The Central Science Chemistry is the study of matter and the transformations it can undergo -Matter is anything you can touch, taste, smell, see, or hear
Research is any activity whose purpose is the discovery of new knowledge. - Basic research leads to a greater understanding of how the natural world operates. Applied research focuses on developing applications developed from research. Most chemists choose applied research as their major focus.
The American Chemistry Council adopted the Responsible Care Program who pledge to manufacture chemicals without causing environmental damage
16. 2 Submicroscopic World Atoms are the basic unit of matter -Elements are made up of 1 type of atom Molecules form when atoms link together. Ex: H 2 O Submicroscopic is the realm of atoms and molecules.
At the submicroscopic level, solid, liquid, and gaseous phases are distinguished by how the submicroscopic particles hold together Phase of Definite matter shape? Solid Phase of matte yes Definite shape? Liquid No Gas no Definite Particle volume? moveme nt yes Slight Definite Particle speed vibration volume? yes Slip past each other No Fast, random
16. 3 Change of Phase In order to change the phase of a substance, you must either add or remove HEAT.
Solid liquid= melting Liquid solid= freezing Liquid gas= evaporation Condensation- gas liquid Heat of fusion- the amount of energy needed to change any substance from solid to liquid and vice versa) Heat of vaporization- the amount of energy required to change any substance from a liquid to gas and vice versa
16. 4 Physical and Chemical Properties Physical properties- describe the look or feel of a substance Chemical properties- characterize the ability of a substance to react with other substances or to transform from one substance to another. During a chemical change, there is a change in the way the atoms are chemically bonded to one another.
Physical change- a substance undergoes a phase change, but NOT it’s chemical identity Chemical change- change that involves a rearrangement of the way atoms are bonded Chemical reaction- new materials form by a change in the way atoms are bonded together
16. 5 Determining Physical and Chemical Changes After a physical change, the molecules are the same as the ones you started with. After a chemical change, the original molecules have been destroyed and new ones are in their place. What are some signs of a physical change? A chemical change?
16. 6 The Periodic Table Most elements are metals Metals are malleable, which means they can be bent without breaking. They are also ductile, meaning they can be drawn into wires. Nonmetals are on the right side, they are poor conductors or electricity and heat, and are brittle. Only 6 elements are metalloids, which have both metallic and nonmetallic properties.
Elements are also organized into periods and groups Each horizontal row is called a period Each vertical column is called a group Periodic trend- as you move across a period the properties of elements gradually change The properties of elements in the same group are very similar
The transition metals include some of the most familiar and important elements. (Ex: Fe, Cu, Ni, Cr, Ag, Au
16. 7 Elements to Compounds Elements are made up of the same type of atom, Compounds are made up of 2 or more elements. (Ex: H 2 O) A chemical formula shows what elements and how many of each make up a compound. The physical and chemically properties of compounds are completely different from the properties of the elements that make it up.
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