Mixtures/Solutions
When we mix water with sugar we get this type of mixture? Give the definition of the type of mixture.
Homogenous mixture - Components are uniformly mixed throughout but are not chemically combined.
What is the definition of a molecule?
Name the parts of the atom and their respective charges.
protons, neutrons, electrons. protons (positive), neutrons (neutral) and electrons (negative)
Define a chemical change? There is more than one correct answer - make sure you explain your answer.
When two or more substances react to produce a different substance. We know we have a different substance when the physical properties of the reactants produce a new product.
What is our simple definition of matter?
Matter is anything that has mass and volume.
When we mix clean sand and water as in our classroom demonstration we have what type of mixture? Give the definition of the mixture.
Homogenous mixture - We can see the components, can easily separate them. They are not chemically combined.
What is the definition of compound?
A compound is a molecule of two or more different types of atoms that are combined together.
Define a solid and how the atoms are arranged
atoms are tightly packed together, moving very slowly when compared to a liquid or gas, solids have definite shape and volume.
Give three chemical properties of matter that we discussed in class?
Reactivity - Ability of a chemical or element to react and change into a new substance during a chemical change
Oxidation (rust) - A new substance is formed when the element or molecule comes in contact with oxygen producing a new substance (rust).
Flammability - The ability of a substance to burn in the presence of oxygen.
When a reactant and a reactant chemically combine they form a _______________.
product
When we boil a mixture or solution and observe the circular motion of the molecules in the boiling liquid we are observing an example of this process. What is the simple name of the process that is used to identify the circular motion.
Convection
Na + Cl2 ---------- ????
What is the product chemical formula and scientific name of the compound?
What are the reactants?
Sodium Chloride (Table Salt)
Chemical Formula: NaCl
Reactants:
Sodium (Na)
Chlorine (Cl2)
Define a liquid and how the atoms are arranged
matter that takes the shape of the container, has definite mass and volume, particles are spaced further apart than a solid, atoms slip and slide against each other, particles are moving faster than a solid but slower than a gas
Explain what happens when a substance burns.
A spark generates the fire needed for the substance to catch fire in the presence of oxygen.
When exothermic reactions happen what happens to the temperature around the reaction?
Water is a mixture that contains various elements. What temperature does freshwater boil at sea level?
What temperature does freshwater freeze?
Don't forget the units or labels for your answers.
100 degrees C
0 degrees C
What is the name of this form of compound?
Solutions are chemically combined and they can be gases, liquids or solids.
Define a gas and how the particles are arranged
particles are moving very fast, spaced very far apart, take the shape of their container, have definite mass but volume can change
When two reactants come together they become a product. When a chemical reaction occurs what must be done to the reactants and the products in order to conform to the Law of Conservation of Matter?
They must be balanced so that the same number of atoms of a given element are found on both sides of the equation.
Temperature rises
How would you remove the sand from a mixture of sand and water?
Explain your answer and develop a procedure for removing the sand from water.
Sand can easily be separated from water by pouring the water through a sieve, screen, or device that would trap the sand and allow the water to pass through into a collection container.
Procedure:
1) Pour homogenous mixture through a screen
2) Collect sand on the screen
3) Collect water in a container
In a solution which is a compound what are the names of the two different parts of a solution and what do they actually do in the solution.
Solute: Is dissolved in the solvent (liquid water)
Solvent: Dissolves the solute (solid green dye)
What is the name of an atom's outermost electrons? What are they responsible for in a chemical reaction?
Valence electrons
They are the outer electrons of an element that react with other outer electrons of other elements that allow the atoms to form new substances during a chemical reaction.
When elements come together for form different substances we learned they can form using these two types of chemical bonds. Name both chemical bonds and define them.
Covalent bond - atoms combine by sharing the outermost electrons forming new substances (products) with different properties than the original reactants.
Ionic bone - atoms combine by gaining or losing electrons forming ions which chemically combine and form new substances (products) that have different properties than the original reactants.
Reactant + Reactant ---------- ????
Product