Question

1. what are isotopes? a. atoms that have the same # of electrons but different # of neutrons b. atoms that have the same # of neutrons but different # of protons c. atoms that have the same # of protons but different # of electrons d. atoms that have the same # of protons but different # of neutrons 7. what do electrons do to an atom? a. give the atom its identity b. sit inside the nucleus c. add weight to the atom d. change the charge of an atom 8. true or false: an object with a density of 2.7 g/ml will sink in water. (water density is 1.0 g/ml) true false 9. what is a compound? a. there is one atom b. there are protons and neutrons c. all of the atoms are the same d. there are different atoms together free response 10. if an object weighs 150 grams and takes up 25 ml of volume, what is show your work below.

Explanation:

Step1: Define isotopes

Isotopes are atoms of the same element, which means they have the same number of protons but different numbers of neutrons.

Step2: Analyze electron - related concept

Electrons are negatively charged particles outside the nucleus. They can be gained or lost, which changes the charge of an atom (forming ions). Protons give an atom its identity, and neutrons and protons add weight to the atom.

Step3: Compare densities

An object sinks in a liquid if its density is greater than the density of the liquid. Given water density is 1.0 g/mL and object density is 2.7 g/mL, since 2.7>1.0, the object will sink.

Step4: Define compound

A compound is made up of different atoms chemically combined together.

Step5: Calculate density for free - response

The density formula is $
ho=\frac{m}{V}$, where $m = 150$ g and $V=25$ mL. Substitute values: $
ho=\frac{150}{25}=6$ g/mL.

Answer:

1. D. atoms that have the same # of protons but different # of neutrons
2. D. change the charge of an atom
3. TRUE
4. D. there are different atoms together
5. 6 g/mL