Answer:
Scientific investigation aims to design and implement an experiment to learn new information, where
development aims to design a product to solve a problem.
Explanation:
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.
A physical change does not change the identity of the substance but the chemical change does.
Example
If you tear or shred a piece of paper it is still paper, but if you pour chemicals on it it will probably change to something else.
Answer:
See explanation
Explanation:
The oxides or hydrides are formed by exchange of valency between the two atoms involved. The group of the atom bonded to oxygen or hydrogen in the binary compound can be deduced by considering the subscript attached to the oxygen or hydrogen atom.
Now let us take the journey;
R2O3- refers to an oxide of a group 13 element, eg Al2O3
R2O - refers to an oxide of group a group 1 element e.gNa2O
RO2 - refers to an oxide of a group 14, 15 or 16 element such as CO2, NO2 or SO2
RH2 - refers to the hydride of a group 12 element Eg CaH2
R2O7 - refers to an oxide of a group 17 element E.g Cl2O7
RH3- refers to a hydride of a group 13 element E.g AlH3
