Select the correct answer.

Haley rubs a cotton cloth along a plastic strip. The plastic strip becomes positively charged. Why did this happen?

What happens to the particles of an object as temperature is added to it or taken away from it

How many moles of Cl2 will produce 0.35 miles of NaCl when reacted with excess Na?

What mass of O2 was used up in the reaction with an excess of SO2 gas if 14.2 g of sulfur trioxide is formed?

Which compound is insoluble in water? (1) KOH (3) Na3PO4 (2) NH4Cl (4) PbSO4

When water is heated, bubbles form in the water. Is this evidence of a chemical reaction? Why? Question 2 options: No, boiling water is a physical change. Yes, the formation of a gas is evidence of a chemical reaction.

Of the following reactions, which one produces oxygen gas? Fermentation Anaerobic respiration Aerobic respiration Photosynthesis

Describe the electrodes in this iron-copper galvanic cell.

What happens to wood when it burns?

El cuerpo humano tiene unos 6 billones de células (6,0x1012) y la población de la Tierra es de unos 8 000 millones de personas. Con estos datos aproximados, calcula las moles de células humanas que hay en la Tierra.

True or false: an apple looks red because it absorbs red light?