Avoiding bias, increases reliability and is important to experimental data. A scientist is investigating the cause of contamination of well water at a specific location. Four residents of the location responded to questions asked by the scientist. The chart below shows their responses. Questions Resident 1’s answer Resident 2’s answer Resident 3’s answer Resident 4’s answer Do you work at the gas station near the well? No Yes No Yes Does anyone in your family work at the gas station? No No Yes Yes Have you observed any change in the quality of well water? Yes No Yes Yes Which of these residents is most likely to provide reliable information? (2 points)

When a majority of scientists worldwide agree on a common explanation to a problem, the explanation is called a (2 points)

A scientific idea becomes valid when it is (2 points)

One group of students is investigating the properties of the bar magnet shown below. The students took a bowl of iron nails, plastic pieces, wood shavings, and paper pieces. The bar magnet was placed inside the bowl for some time and then taken out. Several iron nails were stuck on the bar magnet. The experiment was repeated by several students using different bar magnets. Based on the investigations, which of these theories would the students most likely propose? (2 points)

NASA’s space shuttle program in Florida will end in 2011. Which of these statements best predicts the outcome of this event on the people living in locations near the space center? (3 points)

The table below compares three galaxies.   1 2 3 Type of galaxy Shape Force holding it together Type of matter present Spiral Pinwheel Gravitational Stars, gas, and dust Elliptical Round or oval Electrical Electrons and protons Irregular Undefined Gravitational Stars, gas, and dust The information about galaxies is correct only in (3 points)

One astronomer is studying the nature of an electromagnetic wave emitted by hot gases in the universe. The electromagnetic wave has higher frequency than visible light but lower frequency than gamma rays. What electromagnetic wave is the astronomer most likely studying? (3 points)

Gamma rays are produced by applying (3 points)

Which of these is a part of the geosphere? (2 points)

Infrared radiations are produced when a changing electric field creates a (3 points)