Tutor profile: Carole B.
Subject: Physics (Thermodynamics)
How do you calculate the heat of a system and tell if heat is being absorbed or released?
Using the equation q=mc(delta t) you can find the energy released or gained by a system. If the q value is positive energy is being absorbed into the system. If the q value is negative the system is releasing energy.
Why do atoms bond covalently?
Atoms create covalent bonds to become more stable. When an outermost energy level of an atom does not have 4 pairs of electrons or a complete octet the atom is not stable. In order to become stable it will bond with another atom. This bond is created by sharing valence electrons with another atom to obtain a full outer shell of valance electrons.
Subject: Physical Science
How can you differentiate between a chemical and physical change?
First you need to understand what chemical and physical changes are. A physical change does not change the chemical makeup of the material. The size or shape may be affected an example would be tearing a piece of paper in two but they are both still paper. Chemical changes change the makeup of a material. It is no longer the same as it was before. For example if you take the piece of paper that you tore in half and burn it you have changed it chemically. It no longer has the same properties it did previously.
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