Scientists are studying a pond. Which property can the scientists measure to understand the amount of energy held by the lake water? A. the depth of the lake
B. the color of the water
C. the volume of the lake
D. the temperature of the water

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?

The brightest star in the night sky in the northern hemisphere is sirius. its distance from earth is estimated to be 8.7 light years. a light year is the distance light travels in one year. light travels at a speed of 3.00 × 108 m/s. calculate the distance from earth to sirius in miles. (1 mi = 5280 ft) g

When thorium (90 protons) ejects a beta particle, the resulting nucleus has question 18 options: 87 protons. 88 protons. 89 protons. 90 protons. none of the above