A physical change is any change in a substances form that does not change its chemical makeup. Examples of physical changes are breaking a stick or melting ice. A chemical change occurs when atoms of a substance are rearranged, and the bonds between the atoms are broken or formed. HOPE THIS HELPS!!
Answer:-
Water is highly ordered. In water each oxygen atom is connected to others around it through hydrogen bonding via bridging hydrogen atoms. When a salt like NaCl is dissolved, some of these Hydrogen bonds break.
When a salt like NaCl dissolves in water, the NaCl breaks in to ions Na+ and Cl-.
The water molecules now surround these ions.
The slightly negative oxygen end of water molecule gets near the Na+, while the slightly positive Hydrogen of water molecule gets near the Cl-.
So before salt sample dissolve, the water molecules were highly ordered due to hydrogen bonding. Now after salt dissolve there is a decrease in order and thus an increase in disorder of the water molecules.
Due to increase in disorder, entropy which is a measure of disorder increases. Since entropy increases, delta S for the process is positive.
Answer:
So A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms. These electrons are simultaneously attracted by the two atomic nuclei. A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions.
Explanation:
words to know: covalent bond, electronegativities, and simultaneously
Covalent Bond: A chemical bond formed when electrons are shared between two atoms. Usually each atom contributes one electron to form a pair of electrons that are shared by both atoms.
Electronegativities: the degree to which an element tends to gain electrons and form negative ions in chemical reactions.
Simultaneously: at the same time.
hope this helps!
Max Planck concluded that energy is not continuous and is carried in discontinuous units which he named quanta.
Answer:
True
Explanation:
The majority of the reactions happened with a flow of heat. When there's no heat, the reaction is adiabatic.
For no adiabatic reactions, the heat can be released (evolution) by the system, so the reaction will be exothermic, or absorbed by the system (absorption), then the reaction is called endothermic.
