Monday, May 15th Entry Task Which group is often used to kill bacteria? Schedule: Metalloids, radioactive elements Objective: I can describe the properties of metalloids and radioactive elements Homework Read pages 158-160 very carefully Please have on desk: ISN open to element group foldables

Metalloids A zig-zag line that separates metals from nonmetals Have properties of both metals and nonmetals

Metalloids Silicon is the second-most common element in Earth’s crust Found in groups 13 – 17 Some used in semi-conductors

Radioactive elements The identity of an element is determined by the number of protons in the nucleus. Chemical changes do not affect the nucleus, so chemical changes do not change the identity of the element.

Radioactive elements The nucleus is held together by the strong force even though the protons repel each other. The stability of a nucleus depends on the right mix of protons and neutrons.

Radioactive elements Some elements have an unstable nucleus because they have too few or too many neutrons. When the nucleus is unstable, particles are produced from the nucleus to restore balance. This comes with a release of energy.

Radioactive elements This is called radioactivity. If the production of particles changes the number of protons, the atom is transformed into a different element.

Radioactive elements An isotope is radioactive if the nucleus has too many or too few neutrons. Scientists study radioactivity with a Geiger counter.

Uses of radioactivity To destroy harmful tumors To monitor activity of organs in the body

Radioactive Decay Radioactive atoms produce energy and particles from their nuclei. The identity of the atom changes because the number of protons changes. This is radioactive decay.

Radioactive Decay Radioactive decay occurs at a steady rate that is a property of that isotope. The time that it takes for one-half the atoms in a sample to decay is called a half-life.

The half-life Does not depend on the size of the sample of an isotope. Is not affected by temperature or pressure. A half-life can be less than a second or billions of years.

Tuesday, May 16th Entry Task What are two trends as you move from left to right across the periodic table? Schedule: Radioactive decay activity Objective: I will model the radioactive decay of an element. Homework: Complete activity questions Please have on desk: Pencil, calculator

Wednesday, May 17th Entry Task An element has a dull surface and does not conduct electricity well. What is it? Schedule: Chapter 5 Review Objective: I know and understand the concepts of 5, the Periodic Table Homework: Study Chapter 5 Please have on your desk: Radioactive decay activity

Thursday, May 18th Entry Task What do the elements in group 1 have in common? Schedule: Chapter 5 quiz Chapter 6 introduction Objective: I will demonstrate my understanding of Chapter 5, The Periodic Table Homework: Complete the Chapter 6 title page & introduction Please have on desk: Chapter 5 review

From your journal Review the group number and properties of: Alkali metals - Metals Alkaline earth metals - Nonmetals Transition metals - Metalloids Rare earth metals Halogens Noble gases

Friday, May 19th Entry Task How many words can you make from SCIENCE Schedule: Elements and compounds Formulas and subscripts Objective: I can explain how chemical formulas represent compounds Homework Complete the counting atoms worksheet Read pages 175 - 182 Please have on desk: ISN, textbook

Science Total number of words made out of Science =34 6 letter words made out of science 1). scenic 2). nieces 5 letter words made out of science 1). cines 2). cense 3). seine 4). scene 5). since 6). niece 4 letter words made out of science 1). sine 2). seen 3). sene 4). sice 5). nice 6). ices 7). cees 8). cine 3 letter words made out of science 1). sei 2). sen 3). cis 4). cee 5). sic 6). sin 7). ens 8). see 9). sec 10). nee 11). ice 12). ins 2 letter words made out of science is in si es en ne

What is an element? A pure substance that cannot be separated into anything simpler by chemical reactions or physical means An element has only one type of atom Gold Oxygen

All elements have their own unique properties Appearance – color, shininess, state of matter Melting, freezing, and boiling points # of protons and electrons Atomic mass Reactivity with other substances Density Hardness, texture

Elements are listed on the Periodic Table of the Elements Elements have been placed on the periodic table based on their properties Elements with similar properties are grouped together 3 main groups of elements: Metals Metalloids Non-metals

What is a Compound? A COMPOUND is a pure substance composed of two or more elements that are chemically combined.

Specific Ratios of Atoms! Compounds have Specific Ratios of Atoms! For example, H20 is water, but H2O2 is hydrogen peroxide!

Unique Set of Properties! Every Compound has a Unique Set of Properties! Each compound has a unique set of properties that allows you to tell it apart from other compounds. Each compound has its own physical properties (boiling point, melting point, density, color, etc.). Compounds can also be identified by their chemical properties (reactivity).

Unique Set of Properties! Every Compound has a Unique Set of Properties! A compound has different properties from the elements that form it. For example, sodium (Na) is a shiny metal that reacts with water, oxygen (O2) and hydrogen (H2) are flammable gases. However, sodium hydroxide (NaOH) is a strong base that has many uses including soap making and glass etching.

Compounds can be Broken Down into Simpler Substances Compounds can be broken down into simpler substance through chemical changes. For example, when you open a can of Pepsi, the carbonic acid breaks down into carbon dioxide and water. Compounds cannot be broken down by physical changes.