Tuesday, November 25, 2008

Liquid Density - Hot Water vs Cold Water

In today's activity, the students investigated the question, "Is the density of all water the same?" Using hot, red water heated up in a coffee urn and ice-cold, blue water stored in a cooler, the students tried to determine if one or the other was more or less dense. For the investigation, they had 2, different sized test tubes and a long, plastic pippet at their disposal. The kids tried putting the hot water into the test tube first and then added the cold water. They then tried the opposite. After a lot of experimenting, they discovered that the hot water was "lighter", or less dense than the cold water.

Monday, November 24, 2008

Bird of the Week - Xll

This week's "Bird of the Week" is the Mourning dove. Believe it or not, the Mourning dove is one of the 10 most abundant birds in North America. This medium sized, pigeon like bird is about 9 - 13 inches long with a wing span of approximately 15 - 18 inches. It has a small head with a long pointed tail and a light grayish-brown body. There are black spots on its wings. The sexes similar in appearances, but the males are slightly larger and slightly more colorful, with a bluish crown and pink chest.

Mourning doves feed mostly on ground, especially on relatively bare ground, where they eat seeds. Mourning doves usually feed in pairs or flocks.

In many states in the country, the Mourning dove is a game bird, meaning that it can be legally hunted.

To learn more about the Mourning dove and to hear it's song, click on this link: http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Mourning_Dove_dtl.html

Photo taken from All About Birds.

Friday, November 21, 2008

Liquid Density Column

During Thursday's class, we investigated how different liquids have different densities. Using water, vegatable oil, alcohol, and glycerine, the kids constructed density columns in test tubes

Tuesday, November 18, 2008

Density of Wood Blocks

The Density of Wood Blocks is an excellent, middle school activity. I got the idea from the NSTA publication "Science & Children" about 12 years ago. The activity involves many skills, all of which are part of our 6th grade science curriculum.

Each class is divided into 4 groups and each group is given a set of 6 wood blocks of different sizes. One group has set A, one group has set B, one set C, and one set D. The wood types are oak, ash, pine, and poplar. First, they have to determine the mass of the blocks using a pan balance scale.

Then the kids have to measure the length, width, and height of the blocks to the nearest mm. Using the formula V= L x W x H, they figure out the volume of their blocks. All this data is recorded on their data chart.

Next, they figure out the density of their wood blocks by using the formula D = M / V. They do this using calculators and rounding off to the nearest 0.01 g/cm3. They then find the mean (average) density of their 6 blocks.

Then, using the document camera, the 4 groups share their data with the other groups so that when done, all four groups have all four sets of data.

What really makes this activity come to life is that the then kids graph the density of all 4 woods. They make a volume / mass graph and plot the 6 sets of data points for each block, creating a line graph for each wood. They color code each line and make a key. When done, they have a good, visual picture of the different densities.

Monday, November 17, 2008

Bird of the Week - Xl

This week's "Bird of the Week" is the White-breasted nuthatch. The "upside down" bird is a common bird of deciduous forests and wooded suburbs. The White-breasted Nuthatch can be seen hopping headfirst down the trunks of trees in search of insect food. It frequents bird feeders and takes sunflower seeds off to the side of a tree, where it wedges them into a crevice and hammers them open. In winter, the White-breasted Nuthatch joins foraging(feeding) flocks of Chickadees and Tufted titmice. This behavior helps protect the flock of birds from predators.

The White-breasted nuthatch is about 5 -6 inches long and has a mass of between 18 - 30 grams. It's upper parts are blue-gray with a bright white face and underparts. It's long bill is straight or slightly upcurved. The males and females look alike with the male having a black cap and the female having a grayer cap. They eat insects, seeds, and nuts.

To learn more about the White-breasted nuthatch and to hear it's song and call, click on this link: http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/White-breasted_Nuthatch_dtl.html

Thursday, November 13, 2008

Determining Density

During the past week, we have been learning about Density. The topic is challenging because Density isn't just on thing, but the relationship of two things, mass per unit volume. The students have massed various volumes of water to learn that the relationship of mass to volume in water is 1g : 1ml. Therefor, the Density of fresh water is 1.0 g/cm3. The kids have done some Density word problems for homework and in class, found the Density of various objects by massing them and then determining their volume by displacement. Then, using the formula D=M/V, the kids determined the Density. Answers were rounded off to the nearest 0.01 and the label is grams per cubic centimeter, (g/cm3). Answers were recorded on a data chart.

The kids have used three different types of balance scales: pan balance scale, triple-beam balance scale, and an electric pan balance scale.

Monday, November 10, 2008

Bird of the Week - X

This week's "Bird of the Week" is the Dark-eyed junco. The Junco is a medium sized sparrow that is gray with a black hood and a white belly. It has white, outer tail feathers that are quite visible when it flies. It's eyes are dark, it's legs are pink, and it's bill is "whiteish". The male and females look similar with the females being a little more paler and browner. The first photograph is of a male and the second photograph is of a female.

Junco's are the "snowbirds" of our area, appearing around here only in the winter. They are very common at back yard bird feeders and will sometimes appear in flocks of 25 birds or more. The Junco feeds primarily on the ground, scratching the ground looking for insects and seeds.
To learn more about the Junco and to hear it's song, click on the link:
Photos taken from All About Birds.

Friday, November 7, 2008

Sinking/Floating - Gravity vs. Buoyant Force

Today looked like a kindergarten water table class as the the students explored buoyancy! Using balls, corks, and an eye dropper, the kids experienced what a buoyant force felt like. They tried to combat the force of gravity with the balls and corks, but always lost. They were challenged to see if they could get their eye dropper to float, or suspend, at various levels in their tank of water. They quickly discovered that by adding or subtracting water, they could get the eye dropper to suspend at certain levels. The connection was made that more water meant more mass.

Massing Water

During the past couple of classes we have been investigating the relationship between the mass and volume of water. We massed various amounts of water and recorded the mass and volume for each amount. They looked at their data to see if there was a pattern developing between the mass and volume. They concluded that 1ml of water had a mass of 1g.

Tuesday, November 4, 2008

Bird of the Week - lX

This week's "Bird of the Week" is the Northern mockingbird. The Mockingbird is a medium sized songbird, about 8 - 10 inches long with a wingspan of about 12 - 14 inches. It is pale gray above and whitish below, with a long tail. It has a thin bill. The Mockingbird has two white wingbars and large white patches show in the wings when it flies.

The Northern Mockingbird is known for its long, complex songs that include imitations of many other birds. It is a common bird of hedgerows and suburbs, and has been slowly expanding its range northward. The Northern Mockingbird is a loud and persistent singer. It sings all through the day, and often into the night.

The Mockingbird is found in areas with open ground and shrubby vegetation, such as in parkland, cultivated land, and suburbs. It eats insects and fruit. The male and female birds look alike.

To learn more about the Northern mockingbird and to hear it's song, click on this link: