What happens when a chemical change takes place?

Which two characteristics of data always occur together? High accuracy and high precision, high precision and good validity, low accuracy and low precision, high accuracy and good validity

Who was the first man to walk on the moon?

A car drives from east to west over a bridge supported at either end by two pillars. The bridge and car weight is 80 tons. One pillar is pushing up with a force of 30 N. What force is applied to the bridge at the other pillar?

An astronaut is on a new planet. She discovers that is she drops a space rock from 12m above the groundnut has a final velocity of 3m/s just before it strikes the planet surface. What is the acceleration due to gravity on the planet?

Virginia beach is 15 kilometers wide and 50 kilometers long. if 2 cm of rain falls on virginia beach, how many cubic meters of rain fell on virginia beach?

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