How do you know that aliens don't exist

Why do you think that the speeds of comets increase as they near the sun

To live deep ocean what condition do a fish need to be adapted for

Is water flowing down hill stored energy

Are ultrasound waves high energy waves or low energy waves?

If you hold a balloon by a string and the balloon moves toward your sweater and sticks there, what would you infer? A) That the balloon and the sweater have no charges. B) That the balloon and the sweater have like charges.

Which of these is not a source of the shock waves that lead to protostars?

Which kind of information is known about a person if that person's DNA is in a database? A. how old the person is B. where the person was probably born C. some diseases the person might have D. whether the person is likely to commit a crime

A science teacher ran a marathon. After the race she showed her students the silver blanket she was given to keep her warm. A group of students investigated how the colour of the blanket affected how much infrared radiation is absorbed

Students asked to measure the temperature of a reaction beaker recorded the following temperatures. 103.7°C, 108.4°C, 105.8°C, 104.6°C The actual temperature is 105.1°C. Which measurement is the most precise

Two atoms that are isotopes of one another must have a different number of what? electrons neutrons protons all particles