Science 6 Term 1 Week 4 - Mixtures

[00:00:04]Teacher Learning Resource Travel.

[00:00:12]Science six, term one, week four.

[00:00:15]Mixtures.

[00:00:17]Describe useful everyday examples of uniform and non-uniform mixtures such as solutions and suspensions.

[00:00:27]What is formed when two or more substances or matter like water, coffee and sugar are combined?

[00:00:38]When you mix coffee powder, sugar and water, you form a mixture.

[00:00:46]Can anybody tell the class what is a mixture?

[00:00:51]A mixture is a combination of two or more substances in which each pure substance retains its individual chemical properties. Everyday most matter occurs as mixtures. Matter tends to mix naturally like air, sea water, and pebbles.

[00:01:13]Would you like to know more about mixture?

[00:01:18]What makes a mixture of homogeneous or uniform and heterogeneous or non-uniform?

[00:01:27]Let us see what you think you know about the uniform and non-uniform mixtures and what you want to know about the uniform and non-uniform mixtures by filling up the table below. What we think we know, what we want to know, what we learned, and how we know.

[00:01:47]Later when we are done with our lesson, we shall be answering the last two columns.

[00:01:54]Composed of parts of elements that are all the same kind. What do we call this?

[00:02:02]It's homogeneous.

[00:02:05]Composed of parts of different kinds, heterogeneous.

[00:02:14]Subtopic one, uniform and non-uniform mixture.

[00:02:19]Look at the picture or watch the video of a landfill. Then work with a partner and identify whether the materials shown are still recognizable or not. Put a check mark in the correct column for each material.

[00:02:34]For the substances, soil mixed with water, aluminum mixed with soil, newspaper mixed with water, soft drink inside a bottle, rotten vegetables, rain water. In the second column, components that can be identified, and in the third column, components that cannot be identified.

[00:03:00]Here are the correct answers.

[00:03:04]For day two, activity one, comparing homogeneous, uniform and heterogeneous non-uniform mixture.

[00:03:15]Materials needed different kinds of seeds or nuts, salt, forceps, water, spoon, two glass jars.

[00:03:26]Here is the procedure. Place the different kinds of seeds in a jar. Mix them.

[00:03:35]Label the jar as container A.

[00:03:39]Fill the other glass jar with water.

[00:03:45]Dissolve one tablespoon of salt in the water. Mix the two substances evenly until the salt has completely dissolved.

[00:03:53]Label the glass jar as container B.

[00:03:58]Based on your observations, answer the following questions.

[00:04:03]What kind of mixture did you form when you mix the different seeds in the container?

[00:04:10]Can you still recognize the components of the mixture? Why?

[00:04:17]What type of mixture did you form when you mix salt and water?

[00:04:22]Can you still recognize salt from water?

[00:04:25]Prove your answer.

[00:04:28]What type of mixture is in container A and container B?

[00:04:34]What is your conclusion?

[00:04:38]In our activity, you formed a mixture by combining different substances. Mixtures can be combined in different ways and are classified as either homogeneous uniform or heterogeneous non-uniform.

[00:04:56]A homogeneous mixture is a mixture that has a uniform composition throughout.

[00:05:01]The homogeneous mixture could be in liquid or solid form. Only one phase is seen or visible after mixing the different components.

[00:05:12]Vinegar and sugar solutions are homogeneous mixtures since only a colorless liquid is observed. An alloy is a mixture of different melted metals.

[00:05:23]Air is generally homogeneous.

[00:05:29]Here are the examples. Vinegar, alloy, metal.

[00:05:35]A heterogeneous mixture is a mixture that does not have a uniform composition. The composition of a heterogeneous mixture does not blend throughout.

[00:05:48]The individual substances of a heterogeneous mixture are recognizable or remain distinct. The components of a heterogeneous mixture retain their identities and remain distinguishable.

[00:06:04]The faces or substances are all visible.

[00:06:08]A freshly squeezed orange juice or calami juice is a heterogeneous mixture of juice and pulp. The pulp component floats in a juice component.

[00:06:21]Another example of a heterogeneous mixture is a salad dressing. Salad dressing components are not uniformly distributed throughout vinegar and oil.

[00:06:31]Salad dressing has two liquid layers present as well as solids.

[00:06:39]The substances have not blended smoothly but they remain distinct. Some other examples of heterogeneous mixtures are beach sand, fruit salad, and clouds.

[00:06:50]Beach sand is heterogeneous since you can see different colored particles.

[00:06:55]Clouds contain tiny droplets of liquid water.

[00:07:00]For subtopic two, kinds of mixture, solutions, and suspensions.

[00:07:08]Work with a partner. Observe the seawater in the transparent glass. Look carefully at the bottom of the glass.

[00:07:15]Then discuss your observations with your partner and answer the questions.

[00:07:28]What do you observe at the bottom of the glass?

[00:07:32]For day three, let's have activity number one, forming solutions.

[00:07:39]Materials needed alcohol, water, spoon, cooking oil, two beers.

[00:07:48]For the procedure, prepare two glass jars or beers.

[00:07:54]Fill each container with 200 ml of water.

[00:08:00]Add 50 ml of alcohol in water. Stir and observe.

[00:08:07]Add 50 ml of cooking oil to another container with water. Stir and observe.

[00:08:16]Based on your observations, answer the following questions.

[00:08:22]Which liquid mixes well with water?

[00:08:27]Which is the solute in the solution? How about the solvent?

[00:08:35]What type of solution is formed when two liquids dissolve each other?

[00:08:41]What type of solution is formed when two liquids do not mix?

[00:08:47]What is your conclusion?

[00:08:51]Solutions are homogeneous mixtures having two or more components uniformly distributed.

[00:08:59]A solution is formed when one substance is dissolved in another substance. When a substance is dissolved, it breaks down into molecules. These molecules mix with other molecules of another substance.

[00:09:16]A solution contains solute and solvents.

[00:09:19]When you look at a solution, it is not possible to distinguish a solute from a solvent.

[00:09:29]When you dissolve salt in water, you form a solution. Salt is the solute while water is the solvent. Solute is the substance that is dissolved in a solution. Solvent is the substance in which solute is dissolved.

[00:09:48]You are probably familiar with a solution in liquid form such as tea and lemonade. But solutions can also be a mixture of solids, liquids, and gases.

[00:10:00]They can be a mixture of a solid and a gas, a solid and a liquid, or a gas and a liquid.

[00:10:08]A solution might exist in liquid, solid or gas depending on the state of its solvent. Air is a gaseous solution and its solvent is nitrogen gas. Steel is a solid solution.

[00:10:24]Its solvent is iron and the solute is carbon or solid. Most solutions are in liquid form and have water as the solvent. This is why water is considered by some as a universal solvent.

[00:10:42]A solution of two solid materials is possible. When this happens, an alloy is usually formed. Brass which is used in making furniture is composed of mixture and zinc metals.

[00:10:58]Another example is steel which is composed of carbon and iron metals. It is commonly used in constructing buildings and bridges.

[00:11:10]Let's have activity number two observing characteristics of suspension.

[00:11:16]Materials needed water. Plastic bottle with cap. Food coloring. Cooking oil.

[00:11:22]Beaker.

[00:11:26]For the procedure, fill the beaker with water. Add a few drops of coloring to the water.

[00:11:36]Pour about 3 tablespoons of colored water along with 3 tablespoons of oil into the plastic bottle.

[00:11:46]Seal the bottle with a lid and shake the bottle vicorously.

[00:11:54]Put the bottle down. Observe the mixtures for a while.

[00:12:01]Based on your observations, answer the following questions.

[00:12:07]What happened when you added a few drops of food coloring to the water?

[00:12:13]What kind of mixture is formed when you mix food coloring and water?

[00:12:20]What happened when you poured the colored water along with the oil into the plastic bottle?

[00:12:29]What kind of mixture is formed when you add oil to the colored water?

[00:12:37]What is your conclusion?

[00:12:41]There are some substances that do not mix when combined. They just settle at the bottom or float on top. This kind of mixture is called suspension. Substances like oil, soil, sand, and gravel. Do not mix when placed in water.

[00:13:00]They just settle out when left undisturbed. Gravel and water would settle more quickly because large particles separate more rapidly than small or light particles.

[00:13:14]A mixture of oil and water is a suspension. You can mix oil and water and shake as hard as you like, but they will separate after some time, just like in our activity.

[00:13:28]While water often mixes with other liquids to form solutions, water mixed with oil does not form a solution. Water molecules are strongly attracted to each other while oil molecules are more attracted to their kind.

[00:13:45]When left undisturbed, oil floats above the water because it has a lower density than water.

[00:13:53]Some suspension does not separate because the very tiny particles can stay suspended. For example, whole milk is a suspension of cream and milk. Peanut butter is a suspension of oil and mashed peanuts.

[00:14:10]Oil and vinegar dressing is also an example of suspension. In this kind of mixture, the particle of one substance scatters through another substance without dissolving.

[00:14:23]A suspension has larger particles that are visible. These particles settle out when left undisturbed. Other examples of suspensions are tomato juice and fine sand or silt in water.

[00:14:42]For day four, return to your TWWLH chart. Review your answer in the think column and check if they are correct. Determine whether your questions in the want column were answered during the activities. Then complete the learned and how columns based on what you discovered and learned.

[00:15:05]Classify each mixture as homogeneous, uniform, or heterogeneous non-uniform.

[00:15:14]Salt water, orange juice with pulp.

[00:15:17]Dissolve in tea or coffee. Sand and water. Salad dressing.

[00:15:27]Muddy water. Air. Vinegar. Paint. Soft drink.

[00:15:39]Here are the correct answers.

[00:15:49]Examine the foods and beverages you had for dinner. Identify whether each one is a homogeneous or heterogeneous mixture.

[00:15:58]List the components of each mixture and be ready to share your findings with the class.