Which of the following is a sign that a chemical change has taken place when wood burns?

bubbles

rust

production of a liquid

production of heat

A sample of iron has the dimensions of 2cm times 3cm times 2cm. if the mass of this rectangular-shaped object is 94g, what is the density of iron?

A passenger in the rear seat of a car moving at a steady speed is at rest relative to A. the front seat of the car B. the side of the road C. a pedestrian on the corner ahead D. the wheels of the car

A 10 kg ball has a momentum of 40 kg. m/s. what is the ball's speed?

You have gathered information about which websites your classmates visit to research science questions. What type of graph would best represent this information? A. pie chart B. bar graph C. line graph D. scatter plot

What is the approximate weight of a 20-kg cannonball on Earth? 2 N 20 N 196 N 1,960 N

Which statement correctly compares infrared light to ultraviolet light?

Name the regions of a electromagnetic spectrum from the shortest wavelength to the longest wavelength

a worker climbs a ladder and does 8 J of work on a 2 N object. What is the distance they lift the object

Discuss how electric current is able to flow.

What techniques allow us to identify the presence of different elements?