Answer:
A.
Explanation:
You should NEVER eat or drink anything in a lab area. You never know what chemicals or gases are in the lab, and they can harm you.
Wearing a drawstring hoodie won't protect you from chemicals.
Don't wait to clean up chemicals, immediately get a teacher and clean it up (follow the teachers instructions). You never know what has spilled, and if it is harmful or not, or if there is a certain procedure to clean it up.
Don't change the equipment in the middle of an experiment. This can tamper with your results, and depending on what you are working with, this can be dangerous.
Answer:
The purpose of molecular modeling is to provide a three-dimensional image (either physical or software-based) that allows a chemist to better see the manner in which atoms and molecules can interact. These models can be used to interpret existing observations or to predict new chemical behavior.
Explanation:
It can describe shape and how they connect while forming the electrons.
Answer:
compound light microscope
Answer: X could represent the element of oxidation state (+2) such as (Mg2+, Pb2+, Ba2+, Ca2+, Ba2+, Zn2+, ....etc)
Explanation:
- The formula of the compound XSO4 is a neutral compound that the algebraic summation of the oxidation states of different elements in it must be zero.
- The group SO4 has the oxidation state (2-), that S has (6+) oxidation state and O has (2-) oxidation state, so the oxidation of SO4 = (6+) + (-2*4) = -2.
- It is clear that X must have the oxidation state 2+.
- So, X could be represents by many different elements such as (Mg2+, Pb2+, Ba2+, Ca2+, Ba2+, Zn2+, Fe2+, ....etc)