Answer:
A sample of water boils and releases gas.
Explanation:
Physical change is a change where no any chemical reaction takes place only the chemical composition of matter changes. It is a reversible process .
Burning of newspaper, rusting of iron, plant changes carbon dioxide and water into sugar (photosynthesis) are chemical reaction and irreversible process.
Answer: A is condensation and B is freezing.
The process in which the gas changes to the liquid phase due to the removal of heat is known as condensation. Rains are formed in this way. The water vapour rises. As it raises above it loses heat and then cools down and condenses and comes down as rainfall.
The process in which the liquid changes to a solid on removal of heat is known as freezing. Formation of ice is an example. When the heat is removed at -4 degree Celsius the water freezes to ice.
Answer:
D. the energy release increases the molecular motion but decreases the kinetic
energy of the substance
Newton ,perhaps as many other originations use it as a gravitational law
The chemical formula of the ionic compound is XY₂.
<h3>Ionic compounds</h3>
- Ionic compounds are compounds which are formed from the combination of negatively charged and positively charged ion.
- Positively charged ions are formed by loss of electrons
- Negatively-charged ions are formed from gain of electrons
<h3>Formation of ionic compounds</h3>
During the formation of the ionic compound between an ion X that has a charge of 2+ and ion Y has a charge of 1-, two negatively charged ions of Y are required to form a neutral ionic ionic compound when they react with X.
The chemical the formula of the ionic compound they form is as follows;
X²⁺ + 2Y⁻ ---> XY₂
Therefore, the chemical formula of the ionic compound is XY₂.
Learn more about ionic compounds at: brainly.com/question/13439771
