Select all the correct answers.

Why do the atoms in a piece of copper metal have no net charge?

The charges of the positive and negative copper ions cancel each other out.
The number of electrons surrounding each copper nucleus doesn’t change.
Copper atoms can’t lose electrons without a substance present to gain electrons.
When a copper atom loses electrons, it also loses a corresponding number of protons.
The copper atoms exchange neutrons instead of electrons.

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Electromagnets coils of wire paper clips picked up 10 3 15 6 20 9 25 12 ms. owens' class was studying magnets. ms. owens showed her students how to make an electromagnet using a nail, a d-cell battery, and plastic coated wire. the students wrapped the wire around the nail and then attached the ends to the battery. when they were finished, they tested their magnets by investigating how many paperclips their magnets could pick up. they also tested whether they could increase the strength of their electromagnets by using more coils of wire. they recorded the class average of their results in the data table seen here. ms. owens asked her students to graph their data in a line graph. how should the students label the x-axis on their line graph? a) size of battery b) number of paper clips c) number of coils of wire d) strength of electromagnet

Why is the bottom layer of a trophic pyrimid the