(2) U-238 is the radioisotope used in dating geological formations. Uranium-238 has a half-life of 4.46 billion years, which makes it suitable to date such old formations.
The other options do not have such long durabilities and half-lives.
Answer:
The correct answer is option D.
Explanation:
Step 1: 
Step 2: 
Overall reaction can be determined by adding all the reactions of mechanism:
Reactants in an overall reaction = 
Products in an overall reaction = 
According to question , the role of oxygen gas is product.
Hi there, the correct answer to this would be reactivity because color, melting point, and density are all examples of physical properties.
Answer:
Iron shavings
Explanation:
A substance that has a fixed chemical composition throughout and a mixture is when two or more substances are combined, but they are not combined chemically.
The answer would be 6 e-. This is becuase you are turning a charge of -4 into a +2. In order to do this, you transfer 4 electrons for a neutral charge, and an additional 2 for a charge of +2.
This makes a total charge of +2, and the total transferred electrons 6 e-
