Atoms, Elements and Compounds Chapter 6 Atoms, Elements and Compounds

What are we going to be studying? Transfer of Energy In every chemical reaction, there is a change in energy What we are made up of Atoms are the foundation of biological chemistry and the building blocks for all living organisms Matter is composed of tiny particles called atoms

Atoms Chemistry is the study of matter Matter is anything that has mass and takes up space All living organisms are made up of matter Atoms are the building blocks of matter Atoms are made up of 3 particles Protons Neutrons Electrons

The Structure of an Atom Atoms are made of 3 particles called subatomic particles Protons– are positively charged Neutrons – have no charge Both protons and neutrons are located in the nucleus (center) of an atom Electrons – are negatively charged Electrons are located outside of the nucleus

Elements An Element is a PURE substance that cannot be broken down into other substances Elements cannot even be broken down by physical or chemical means. There are over 100 known elements 92 Elements occur naturally Each element has a unique name and symbol

Non-naturally occurring elements When we create new elements by combining 2 other elements, called bombarding Cyclotron - there is one at MSU The nuclei are fused together These only last for a fraction of a second Used for research

The Periodic Table of Elements Horizontal rows are called periods Vertical columns are called groups Number of valence electron by groups

Chapter 6 RFC 1 #19 - Chart ELEMENT ATOMIC SYMBOL ATOMIC # MASS # # OF PROTONS # OF NEUTRONS # OF ELECTRONS # OF VALENCE ELECTRONS HYDROGEN H 1 CARBON C 6 12 4 NITROGEN N 7 14 5 OXYGEN O 8 16 PHOSPHORUS P 15 31 SULFUR S 32

# of subatomic particles # protons = atomic # # electrons = # of protons (for neutral atoms) # neutrons = rounded mass # - atomic # When we round we use the .5 rule

Isotopes Isotopes are atoms of the same element that have the same number of protons and electrons, but have a different number of neutrons. Because they have a different number of neutrons they have different masses.

Radioactive Isotopes Although atoms with different number of neutrons have the same overall charge, the stability of these atoms differ. When a nucleus decays, or breaks apart, it gives of radiation that can be detected and used for many applications.

Radioactive Isotopes The half-life, or the amount of time it take for half of the radioactive isotopes to decay, can be used to determine the age of an object Carbon dating How old are rocks/fossils Tracing molecules – cancer diagnosis

Compounds A compound is a pure substance formed when two or more different elements combine. Are always formed from a specific combination of elements in a fixed ratio Ex - water

Compounds Compounds are chemically and physically different from the elements that make them up. Its like a family mom, dad, and child are physically and chemically different

Compounds Compounds cannot be broken down into simpler compounds or elements by physical means, however they can be broken down by chemical means. Chemical means – chemical reaction

Compounds Each compound has a chemical formula This formula is made up of the chemical symbols for each element they contain They also include the number of atoms of those element