How could you tell if a sample of matter is an element

Two samples of carbon come into contact. A heat transfer will occur between sample A and sample B. What must be true for heat to transfer from sample A to sample B? The average kinetic energy of A is greater than that of B.

Which is the main type of element found in the upper right part of the periodic table

When balancing a chemical equation, what are the large numbers that we adjust?

What do decomposer and consumers have alike?

When a piece of magnesium is connected to an iron pipe, the iron is prevented from corroding. Which of the following is the best explanation? Magnesium reacts with the ground water to form a protective coat on the iron pipe of Mg (OH) 2.

Be sure to answer all parts. Which product (s) form (s) at each electrode in the aqueous electrolysis of the following salts? Select as many as apply.

True or false. elements in the same period have the same number of valence electrons

A base a. causes phenolphthalein indicator to change from colorless to pink. b. donates a proton in a proton transfer reaction. c. accepts electrons in an electron transfer reaction. d. produces hydrogen ions in solution. e. does none of the above.

Which of these is an indicator that a chemical reaction has occurred? precipitate forms temperature remains the same color is diluted mass increases

The half-life of isotope X is 3 days, how long will it take for one half of 10g sample to decay