science final 1/24/25 Flashcards
What caused the Flint water crisis?
The water source was switched to the Flint River without proper treatment, causing lead contamination due to corroding pipes.
What was one of the major health impacts of the Flint water crisis?
Lead poisoning, especially affecting children, which can lead to developmental and neurological issues.
Which type of reaction absorbs heat?
Endothermic reactions.
Which type of reaction releases heat into the surroundings?
Exothermic reactions.
Give an example of an endothermic reaction.
Photosynthesis, melting ice.
There are multiple right answers for this one! :D
Give an example of an exothermic reaction.
Combustion of wood or gasoline.
In a Bohr model, what determines the number of electrons?
The atomic number of the element.
How do you determine the number of protons in an atom?
The number of protons is equal to the atomic number of the element.
What is the maximum number of electrons that can be placed in the second energy level?
8 electrons.
What charge do neutrons have?
Neutrons have no charge (neutral).
Which subatomic particle orbits the nucleus of an atom?
Electrons.
What is the charge of a proton?
Positive.
What group contains the noble gases?
Group 18.
Where are metals typically located on the periodic table?
Metals are typically on the left side and center of the periodic table.
What properties do alkali metals (Group 1) have?
Alkali metals are highly reactive, soft, and have one valence electron.
What is an example of an element?
Oxygen (O).
of course there are many answers 🙃
What is an example of a compound?
Sodium chloride (NaCl).
What is an example of a mixture?
Salad
Can a mixture be separated by physical means?
Yes, mixtures can be separated by physical methods.
Is this equation balanced?
H2 + O2 → H2O
No, the equation is unbalanced because the number of atoms of hydrogen and oxygen is different on both sides.
Is this equation balanced?
2H2 + O2 → 2H2O
Yes, it is balanced because the number of atoms of each element is the same on both sides.
What is a synthesis reaction?
A synthesis reaction occurs when two or more substances combine to form a new compound.
Example: A + B → AB.
What is a decomposition reaction?
A decomposition reaction occurs when a compound breaks down into simpler substances.
Example: AB → A + B.
What happens in a double displacement reaction?
Two compounds react and exchange parts to form two new compounds.
Example: AB + CD → AD + CB.
What pH range do acids fall into?
pH less than 7.
What pH range do bases fall into?
pH greater than 7.
If a substance has a pH of 3, is it an acid or a base?
Acid.
If a substance has a pH of 10, is it an acid or a base?
Base.
What is a neutralization reaction?
A neutralization reaction is a chemical reaction between an acid and a base to produce a salt and water.
Ex. HCl + NaOH → NaCl + H2O
What happens to the pH of a solution during a neutralization reaction?
The pH moves closer to neutral (pH 7).
