⚛️ Atoms & Particles
This is the smallest unit of an element that still retains its physical and chemical properties.
What is an atom?
The first electron shell can hold a maximum of this many electrons.
2
This type of bond occurs when atoms share electrons.
covalent bonds ( think like cosports sharing)
Water has this property, meaning it resists changes in temperature.
high specific heat
The four main elements that make up most living things.
oxygen, carbon, hydrogen, and nitrogen
These three subatomic particles make up atoms
protons, neutrons, and electrons
The second shell can hold this many electrons.
8
This type of bond occurs when oppositely charged ions are attracted to each other.
ionic bond
Ice floats because of this property.
solid water being less dense than liquid water
Humans also contain small amounts of these three elements.
calcium, phosphorus, and sulfur
The atomic number of an atom determines this.
number of protons
Electrons in the outermost shell are called this
valance electrons
This weak bond helps stabilize water molecules but doesn’t form molecules.
hydrogen bonds
Water is called the “universal solvent” because it dissolves these substances.
hydrophlic= likes water
Sodium, chlorine, and magnesium are examples of this type of element in the body.
minor elements
Isotopes have the same number of protons but different numbers of these.
neutrons
Atoms become this when they gain or lose electrons.
Ions
When electrons are shared unequally, the bond is called this
polar covalent bond
The sticking together of water molecules due to hydrogen bonding is called this.
cohesion
Iron, iodine, and selenium are examples of these.
trace elements
This is the average mass of all isotopes of an element.
atomic mass
Atoms are “happy” when this condition is met with their valence shell.
when the outer shell is full
Molecules made of more than one type of atom are called this.
compound
A lot of energy is needed to turn water into vapor because of this property.
high heat of vaporization
Out of 91 naturally occurring chemical elements, this many are found in the human body.
24