Chemical Reactions
Chem is Tree
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Science
Knowledge
100
In a chemical reaction the substances to the right of the arrow are called this/these?
What is/are products?
100
What are the parts of a chemical reaction?
Reactants and products
100
A substance that enters a chemical reaction is called this.
a reactant
100
The smallest unit of matter is called a/an _________.
an atom
100
What is it called when both sides of a chemical equation have equal numbers of each element?
A Balanced Equation
200
hydrogen + oxygen → water
Where are the reactants and products in this chemical reaction?
Reactants: hydrogen and oxygen
Products: Water
200
In the formula 5CaSO4,how many oxygen atoms do we have?
20
200
How many Aluminum atoms are in the products of this chemical reaction?
Al + O2 → Al2O3
2
200
What is something that can be observed about a substance, such as color, smell, or boiling point?
What is a property?
200
What is it called when both sides of a chemical equation do not have equal numbers of each element?
unbalanced
300
How many Carbon atoms are in one molecule of NaHCO₃?
1
300
What are the reactants in this chemical reaction?
What are ethylene and water.
300
Is this a balanced or not balanced equation?
H2S + NaCl → HCl + Na2S
Not balanced
300
A process in which atoms rearrange to form new substances.
What is a chemical reaction.
300
State the Law of Conservation of Mass.
matter can not be created nor destroyed, just rearranged
400
A small number written below and to the right of an element symbol, indicating the number of atoms of that element present in the molecule or compound.
What is a subscript.
400
The tiny pieces that all matter-all the stuff in the world-is made up of.
What are atoms?
400
During a chemical reaction, atoms rearrange to form _______ groups of atoms.
What is form different groups of atoms.
400
Give an example of a chemical property.
400
Is this equation a balanced or not balanced chemical equation?
P4 + O2 → P4O2
balanced
500
How many oxygen are in 2C6H8O7 ?
What are 14?
500
This is a group of atoms joined together in a particular way.
What is a molecule.
500
All of the following are examples of chemical change except:
Increase in temperature, release of light, formation of a solid, melting of ice
melting of ice
500
This is a chemical process that absorbs energy, usually in the form of heat, from its surroundings, causing the surroundings to feel colder.
What is an endothermic reaction.
500
Put the following in order from smallest to largest:
atom, compound, molecule
What would be an atom, a molecule and the largest being a compound.
600
Chemical reactions change substances into different substances by _________ and ________ chemical bonds.
What is breaking and forming chemical bonds.
600
If the mass of Hydrogen is 4g and that of Oxygen is 12g, (the reactants) when mixed together, what would be the mass of the product?
What is 16 grams.
600
Both mass and energy can neither be created or destroyed, but can be ______________.
What is transferred.
600
Mass will always remain constant but can be changed in what ways?
What is phases or states of matter.
600
Explain the difference in a Physical change and a Chemical reaction.
A physical change alters the form or appearance of a substance without changing its chemical composition, while a chemical reaction (or chemical change) involves the formation of new substances with different chemical compositions.