When predicting the products of a double replacement reaction, are you allowed to switch the order of the products? (like does that mess anything up if the order matters) ex. AB + CD -> AD + CB

When the earth was formed and cooled, why did nickel and iron end up in the center of the earth while basalt and granite ended up in the outer layers

You encounter a solution that is acidic and you decide to test it by adding a small amount of a strong acid. the ph lowers slightly but is approximately unchanged, and still remains acidic. what can you say about the solution? a. it is a buffer solution. b. it is not a buffer solution it is a strong acid solution. d. the solution has been neutralized. e. the solution has excess acid present

Name the element in group 17, period 2. (periodic table)