Chapter 6 Lesson 2 Structure of the Atom

Bell work Day 1 Explain the structure of an atom. For example: An atom has a central area called a ________________where the positive ______________ and neutral _____________ are located. The electrons have a _______________ charge and are located in the ________________ _____________ which is outside the nucleus.

Learning Goals for this Lesson Students will be able to Describe the structure of an atom including the charges of each subatomic particle. Explain where the majority of the mass of an atom is located.

Chapter 6 Lesson 2 2: The Structure of Atoms Atoms: Smallest unit of matter that cannot be divided and still be the same element. Each type of element has a different number of subatomic particles (protons, neutrons, and electrons)

Inside the Nucleus Nucleus: center of the atom where majority of mass is. Composed of: protons (positively charged particles) and neutrons (neutral particles).

Electron ELECTRONS… Electrons are negatively charged particles that occupy the space in an atom outside the nucleus. An electrons negative charge offsets the positive charge of protons. In a neutral atom, there is always the same number of protons as there are electrons. 7 protons (+), 7 electrons (7-) =a neutral atom If there are 7 protons (+7), then there will be 7 electrons (-7) =a neutral atom (0 charge)

Electron Cloud THE CLOUD… Electron Cloud- a region surrounding the nucleus where one or more electrons are most likely to be found. Finding their exact location at any point in time is much more difficult. Think of a ceiling fan. As the blades spin faster it is hard to tell the exact location of a single blade. Electrons zip around the nucleus at the speed of light… Think of how hard it would be to determine their exact location?????

Learning Goals for this Lesson You will be able to Describe the structure of an atom including the charges of each subatomic particle. Explain where the majority of the mass of an atom is located. Differentiate between a neutral atom, and ion, and an isotope Explain how you can tell what type of atom you are observing.

Electron Energy: Electrons traveling closer to the nucleus are STRONGLY attracted to it and have LESS energy. Electrons farther away from nucleus are LESS attracted to it and have MORE energy. Let’s Think About It… Why do you think valence electrons (electrons circling farthest away from the nucleus) are more likely to be part of a chemical reaction?

DID YOU KNOW ???? If an atom were the size of a sports arena, its nucleus would be just the size of a pea. If you compacted all the atoms in a person they would fit on the head of a needle.

The Size of Atoms Properties of Atomic Particles… Protons are positive, electrons are not. Neutrons have no charge so they can’t be bought  An atom is the smallest building block of matter BUT…. An atom is made up of even smaller subatomic particles. Protons and neutrons are about the same size and weigh 1 AMU. Electrons are smaller and have only about 1/200 the mass of a proton or neutron. Sooooo….you could fit 2,000 electrons into one proton!!!!

Differences in Atoms Atomic Number- The number of protons in the nucleus of an atom of a element. ALL ATOMS OF THE SAME ELEMENT HAVE THE SAME NUMBER OF PROTONS…. ALWAYS!!!!!!! Every element on the periodic table has a different atomic number thus, a different amount of protons. Each time you add an proton, you change the element.

Neutrons and Isotopes Isotope…The fat atom is dope!!!!! Neutrons have no charge and help hold the nucleus together. Isotopes are atoms that have extra neutrons in the nucleus. Because neutrons have no charge adding neutrons does NOT change the charge of the atom. However, it does change the atomic mass.

Electrons and Ions However, atoms can gain or loose electrons during chemical bonding. Ion- an atom that has a charge because it has gained or lost an electron Losing an Electron = Positive ion Na+ has 11 protons but only 10 electrons Gaining an Electron = Negative ion Cl- has 17 protons but has 18 electrons Remember…all atoms start out neutral with equal positive and negative charges Protons = Electrons

Practice Questions 1. Where are the positively charged particles located in an atom? 2. Where is the mass of an atom located? 3. What is the difference between a neutral atom, an ion, and an isotope?

Practice Questions ANSWERS 1. Where are the positively charged particles located in an atom? Positive protons are located in the nucleus of the atom 2. Where is the mass of an atom located? The mass of an atom is made of the protons and neutrons which are both in the nucleus  3. What is the difference between a neutral atom, an ion, and an isotope?

Learning Goals for Lesson 6.2 Students will be able to Describe the structure of an atom including the charges of each subatomic particle. Explain where the majority of the mass of an atom is located. Differentiate between a neutral atom, and ion, and an isotope Our focus today 11/2 Explain how you can tell what type of atom you are observing.

Review these terms with me . . . . Matter An atom with an unequal amount of protons and electrons is an _______ (charged particle) An atom that has LOST an electron is called a ____________ _______. An atom that has GAINED an electron is called a ____________ _________. An atom that has an equal number of protons and electrons _______________ An atom that has more neutrons than most other atoms of that element Smallest unit of matter is an ________ __________________

How do we know whether an atom is neutral or Charged (Ion)? 1. Copy and complete this sentence: Neutral atoms have an equal number of positive _____________ and negative ________________.

How do we know whether an atom is neutral or Charged (Ion)? 1. Copy and complete this sentence: Neutral atoms have an equal number of positive __PROTONS____ and negative __ELECTRONS_____.

2. Copy and complete this sentence: A POSITIVE Ion has more positively charged _______________ than it has negatively charged _________________.

2. Copy and complete this sentence: A POSITIVE Ion has more positively charged ____Protons___________ than it has negatively charged ___Electrons_________.

3. Copy and complete this sentence: A NEGATIVE Ion has more positively charged _______________ than it has negatively charged _________________.

3. Copy and complete this sentence: A NEGATIVE Ion has more negatively charged ___Electrons____________ than it has positively charged __Protons_______________.

4. Copy and complete the sentence below Atoms of the same element that have different numbers of _____________ are called Isotopes.

4. Copy and complete the sentence below Atoms of the same element that have different numbers of _neutrons_____ are called Isotopes.

Practice with me  Determine which element the atom is and then whether it is neutral, a positive ion, a negative ion or an isotope. An atom with an atomic number of 8 with no charge. _________________ An atom with an atomic number of 11 with a charge of +1 (Na+)____________ An atom with 7 protons and 8 electrons. ________________

An atom with 17 protons and 18 electrons. _________________ An atom with 6 protons , 6 electrons and 8 neutrons (2 more neutrons than the standard atom) __________ An atom with an atomic number of 53 and a charge of -1 (I -) _____________