4. Methods scientists use to determine if a change was physical or chemical

Round 23.455 cm into 4 significant figures

Engineers increase output in crop production by combining the strengths of two plants. This can be done by using one plant to pollinate a different plant so that their strengths are combined into a new plant. What is this technique called?

A catalyst is used to increase the reaction rate of a chemical reaction. a catalyst achieves this by A. increasing the activation energy. B. decreasing the kinetic energy. C. decreasing the activation energy. D. increasing the kinetic energy.

What 2 states of matter are fluids?

What is the definition of tributary

How many atoms are in 151 g of calcium?

Which statements about the formation of the solar system are true and in a correct order? A. A black hole collapsed to form the sun; small planetary objects formed; small planetary objects collided with each other to form larger objects. B.

Which is an important step in the alternate method for balancing equations in redox reactions? a) indicating the types of bonds found in the molecules. b) determining the speed at which reactions take place.

How many moles of NH3 can be produced from 24.0 mol of H2 and excess N2

An ecosystem contains all the biotic and abiotic factors in an area. answers true or false