A change does not change what a substance is. If heat is added to ice, a physical change occurs because only the of matter has changed. The term for changing a solid to a liquid is . Adding more heat can turn the water into a gas, or . The term for changing a liquid to a gas is . Changes of state can be reversed as well. A gas turns into a liquid by . A liquid turns into a solid by . On very rare occasions, a solid turns into a gas through . The reverse is a gas turning into solid, or . change produces a new substance because a chemical reaction has taken place. We know baking a cake is a chemical change because the flour, eggs, sugar, and other ingredients cannot be returned to their original structures. We know that a chemical change occurs when heat or is released or absorbed, when a or bubbles form, or when a solid or forms

physical, state, melting, vapour, evaporation, condensation, freezing, sublimation, deposition or reverse sublimation, chemical, energy, effevescence and liquids are suitable terms to fill the gaps. See the explanaition

Explanation:

Changes of state are physical changes in matter. They are reversible changes that do not involve changes in matter's chemical makeup or chemical properties. Common changes of state include melting, freezing, sublimation, deposition, condensation, and vaporization. Thus

A physical change does not change what a substance is. If heat is added to ice, a physical change occurs because only the state of matter has changed. The term for changing a solid to a liquid is melting. Adding more heat can turn the water into a gas, or ___vapour. The term for changing a liquid to a gas is evaporation. Changes of state can be reversed as well. A gas turns into a liquid by condensation. A liquid turns into a solid by freezing. On very rare occasions, a solid turns into a gas through sublimation. The reverse is a gas turning into solid, or deposition or reverse sublimation___. chemical change produces a new substance because a chemical reaction has taken place. We know baking a cake is a chemical change because the flour, eggs, sugar, and other ingredients cannot be returned to their original structures. We know that a chemical change occurs when heat or energy is released or absorbed, when a effevescence or bubbles form, or when a solid or liquids forms.

Also note the following points about physical and chemical change.

Physical changes are changes in which no bonds are broken or formed. This means that the same types of compounds or elements that were there at the beginning of the change are there at the end of the change. Because the ending materials are the same as the beginning materials, the properties (such as color, boiling point, etc) will also be the same.  A physical change is a change to a sample of matter in which some properties of the material change, but the identity of the matter does not. When we heat the liquid water, it changes to water vapor. But even though the physical properties have changed, the molecules are exactly the same as before.

Chemical changes occur when bonds are broken and/or formed between molecules or atoms. This means that one substance with a certain set of properties (such as melting point, color, taste, etc) is turned into a different substance with different properties. Chemical changes are frequently harder to reverse than physical changes.

One good example of a chemical change is burning a candle. The act of burning paper actually results in the formation of new chemicals (carbon dioxide and water).

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2