comparing kinds of matter chapter 5 lesson 2: elements
TRANSCRIPT
Comparing Kinds of Matter Chapter 5
Lesson 2: Elements
REVIEW Lesson 1
Measures Weight
• NEWTONS
• AND
• POUNDS
The amount of matter in an object
MASS
How strongly gravity pulls on an object
WEIGHT
Measures Volume
• MILILITERS AND CUBIC
CENTIMETERS
Measures how much space matter takes up
VOLUME
Measures Mass
KILOGRAMS
AND
GRAMS
the amount of mass for each cm3 of a substance
Density
Resistance to sinking
• Buoyancy
Imaginary “skin” that rests on the surface of water
• Surface Tension
What forms can matter have?
• Solid
• Liquid
• Gas
Have a definite shape and volume
• Solids
Have an indefinite shape; volume takes the shape of its container
• Liquid
Have an indefinite shape and volume
•Gas
Lesson 2: What is an Element?
• is a material that cannot be broken down into anything simpler by chemical reactions
• chemical element is the simplest form of matter
What is matter made of?
• all matter is made up of the same set of building blocks
Important properties of elements
• state of matter at room temperature (Most elements are solids, some are gases, and a few are liquids)
• Examples:
• Solids: Iron (Fe), Nickel (Ni), Cobalt (Co)
• Liquids : Mercury (Hg)
• Gas: Helium (He), Oxygen (O)
Important Properties of Elements
• the way they combine with other elements (some elements are likely to combine with other elements to form new substances. These elements are more chemically reactive) – Fluorine (F)
elements are of three types:
• metals
• nonmetals
• metalloids
Metals, Nonmetals, or Metalloids
• Metals are elements that share common properties such as shiny, conductivity, flexibility (iron, cobalt, nickel)
• Nonmetals are elements that are dull, poor conductors and brittle
• Metalloids are elements with properties that are in between
Atom• the smallest unit of an element that retains
the properties of that element
• Any element listed on the periodic table consists of atoms. Hydrogen, helium, oxygen and uranium are examples of types of atoms.
What are atoms and molecules made of?
• nucleus is the center of an atom
• the nucleus is made of protons, and neutrons• A proton is a particle with one unit of positive
electric charge (number of protons in an atom is the atomic number)
• A neutron is a particle with no electric charge
• An electron is a particle with one unit of negative electric charge
• Electrons move around in the space outside the nucleus
Molecules• . Molecules are small particles that make up all
living and non-living things
• particles with more than one atom joined together
• most of the atoms in the world exist as part of a molecule, not on their own
• objects in the world are just many molecules grouped together
Example of a Molecule
• Carbon DioxideLess than 1% of the air is carbon dioxide, but it is essential for life. Plants use carbon dioxide to build energy-rich molecules.CO2
1 black carbon atom2 red oxygen atoms
What are the most common elements?
• In space, the most common elements are hydrogen and helium.
• On Earth, elements such as hydrogen and any of these: oxygen, silicon, aluminum, nitrogen, iron, and calcium are among the most common