To develop a product that warms people's hands, would you use an exothermic or endothermic reaction? Why? A) Endothermic; that way the reaction will absorb heat.
B) Exothermic; that way the reaction will absorb heat.
C) Endothermic; that way the reaction will release heat.
D) Exothermic; that way the reaction will release heat.

Match the following terms describing electrical events with the correct phases of the cardiac cycle. the ventricular muscle cells depolarize at the start of this phase. during this phase, na+ entry through the funny channels causes the pacemaker potential of sa nodal cells to gradually become less negative until it reaches threshold. the ventricular muscle cells repolarize right before this phase. the cytosolic concentration of calcium in the contractile cells of the ventricle is highest during this phase. a. isovolumetric relaxation b. ventricular ejection c. isovolumetric contraction d. ventricular filling

(drag each tile to the correct location.) categorize each term as something that is typical of a scientific theory, a scientific hypothesis, or both. - a tentative statement used to guide scientific investigations. - makes predictions about future events. - can be tested by many independent researchers. - based on observations of natural phenomena. - a well-established, highly reliable explanation.

Describe your dna model. which part do the straws represent? the pushpins? the paper clips and the black dots you made with the marker?