question 1\nwhich of the following is a physical change?\n○ a pencil is sharpened\n○ helium is inert (does…

question 1\nwhich of the following is a physical change?\n○ a pencil is sharpened\n○ helium is inert (does not react with anything)\n○ hydrogen burns in the presence of oxygen and forms water\n○ vinegar reacts with baking soda to produce a gas called carbon dioxide

question 1\nwhich of the following is a physical change?\n○ a pencil is sharpened\n○ helium is inert (does not react with anything)\n○ hydrogen burns in the presence of oxygen and forms water\n○ vinegar reacts with baking soda to produce a gas called carbon dioxide

Answer

Brief Explanations:

A physical change alters the form or appearance of a substance without changing its chemical composition. Sharpening a pencil only changes its physical shape. Helium's inertness is a chemical property. Hydrogen burning and vinegar - baking soda reaction are chemical changes as new substances are formed.

Answer:

a pencil is sharpened