What phylum does a star fish belong to

A uranium-235 sample starts with 200 atoms, and 700 million years later, there are 100 atoms. What is the half-life of uranium-235? A. 350 million years B. 235 years C. 100 years D. 700 million years

What is not the purpose of peer review in science? to validate conclusions to conduct secret research to check the accuracy of data to obtain feedback from other scientists

In the laser range-finding experiments of Example 17.10, the laser beam fired toward the moon spreads out as it travels because it diffracts through a circular exit as it leaves the laser.

How do a neutron and a proton compare? O A. The neutron has much less mass. O B. The neutron is farther from the nucleus. O C. They are equal in number in a neutral atom. D. The proton has a positive charge, while the neutron has no charge.

Describe the relative energy of the electrons in the shells of a calcium atom

April swims 50 m north and then turns and swims 20 m back to the south. What is her velocity if it takes her 60 seconds?

All the colors of visible light can combine to form white light. a. True b. False

If the results of a study do not support a hypothesis, it means that the experiment failed.

How does a rubber band obey the law of conservation of energy?

Shane observes that an upward force pushes him up when he sits on a chair. Based on his observation which statement is correct Friction can act at a distance. Normal force can act at a distance. The chair applies a non-contact force called friction.