Lab Safety
Atomic Structure
Components of a Lab Report
Ions
Isotopes
100
Is it safe to taste chemicals in a lab?
No. It is not safe to taste chemicals in a lab because they may be toxic, corrosive, or unknown, and even small amounts can cause poisoning, burns, or serious health harm.
100
Name the three main subatomic particles.
It is the proton, neutron, and electron.
100
Explain what the aim of a scientific report is used for.
It states what the experiment is trying to find out.
100
What is an ion?
An atom (or group of atoms) that has gained or lost electrons and has an overall charge.
100
What is an isotope?
Atoms of the same element with the same number of protons but different numbers of neutrons.
200
What does this sign mean?
Flammable
200
What is the maximum number of electrons in the second shell?
8 electrons.
Remember:
First shell = maximum of 2 electrons.
Second shell = maximum of 8 electrons.
Third shell = maximum of 8 electrons.
200
What is the independent variable?
A student changes the amount of sunlight a plant receives and measures the height of the plant after 2 weeks.
IV = Amount of sunlight.
Reasoning:
IV is the variable that you change on purpose in an experiment. The DV is what is measured.
200
What is a positive ion called?
A cation.
*Remember that t is similar to a +.
200
True or False.
An isotope is electrically neutral.
True.
*An atom is also neutral. However, an ion is electrically charged.
Reasoning:
An isotope is defined by having the same number of protons but a different number of neutrons.
Charge depends on protons (+) and electrons (−), not neutrons.
In a neutral atom, the number of protons = electrons, so the charges cancel out.
300
How can you prevent accidents like spills, breakages, or mixing up equipment?
Some examples:
Keeping your workspace clear and uncluttered.
No running.
Follow instructions carefully.
300
A student observes that in a solid the particles are tightly packed and only vibrate, in a liquid the particles are close but can move past each other, and in a gas the particles are far apart and move freely.
What does this tell you about how particles are arranged and how they move in each state of matter?
Solids have tightly packed particles that vibrate in place.
Liquids have particles that are close together and can move past each other.
Gases have particles that are far apart and move freely.
300
What are the independent variable (IV) and the dependent variable (DV)?
Independent Variable (IV): Weeks of practice
Dependent Variable (DV): Words per minute (typing speed)
300
Why do atoms gain or lose electrons to form ions?
To achieve a stable outer electron shell.
300
What happens if an isotope is unstable?
It becomes radioactive. Also known as radioisotopes.
400
Name one type of safety equipment used in Science.
Some examples:
Safety goggles (eye protection)
Lab coat / protective clothing
Gloves (e.g. nitrile gloves)
Face shield
Closed-toe shoes
Mask / respirator (for fumes or dust)
Hair tie / hair restraint (to keep hair secure)
Ear protection (earmuffs or earplugs, when needed)
400
Calculate how many electrons magnesium has in its 3rd shell.
There are 2 on its outermost shell.
Remember:
First shell = maximum of 2 electrons.
Second shell = maximum of 8 electrons.
Third shell = maximum of 8 electrons.
400
A graph shows that as the independent variable increases, the dependent variable also increases in a consistent upward straight line.
What does this relationship suggest about the variables?
This suggests a positive relationship, meaning the dependent variable increases as the independent variable increases.
400
An oxygen atom has 8 protons and 8 electrons. It gains 2 extra electrons during a reaction.
What is the charge of the ion formed?
It now has 8 protons and 10 electrons.
There are 2 more negative charges than positive charges.
The ion has a −2 charge (negative ion).
400
From the example below, what are 2 characteristics of an isotope?
Example: Chlorine-35 or 35Cl
•Element symbol followed by a dash and the mass number
•Element symbol with the mass in the upper left (similar to standard atomic notation)
500
Is it safe to clean up a chemical spill without notifying the teacher?
No. It is not safe to clean up a chemical spill without notifying the teacher because the substance may be hazardous or require specific cleanup procedures and equipment.
500
If an atom has 11 protons and 12 neutrons, what is its mass number?
P + N = M
23
P + N = M
11 + 12 = 23
500
A student observes that when the temperature increases, particles move faster and collide more frequently due to increased kinetic energy.
Write a hypothesis in the “If… then… because…” format based on these results.
If the temperature of a substance increases, then the particles will move faster and collide more frequently because they gain kinetic energy.
500
What happens when an atom loses electrons?
It becomes a positive ion (cation).
Reasoning:
The atom has fewer negative charges (electrons) than positive charges (protons).
This leaves an overall positive charge.
500
True or False:
Isotopes are atoms with the same number of neutrons, but different numbers of protons.
False:
Isotopes are atoms with the same number of protons, but different numbers of neutrons.
Reasoning:
The number of protons determines the element (e.g., carbon always has 6 protons).
If the number of protons changes, it becomes a different element, not an isotope.
Isotopes keep the same element identity but vary in neutrons, which changes their mass.