Atomic Basics
Anything that has mass and takes up spaced is called ...
matter
Matter includes solids, liquids, and gases because each has mass and occupies space.
Which subatomic particle has a +1 charge and stays in the nucleus?
A proton
Protons have a positive charge and sit in the nucleus.
What do we call the electrons in an atom's outermost occupied energy level?
Valence electrons
Valence electrons determine how an atom is likely to bond.
In which type of bond do atoms transfer electrons?
ionic bond?
Electron transfer creates oppositely charged ions that attract.
Which choice is a compound: O, O₂, or NaCl?
NaCl
NaCl contains sodium and chlorine, two different elements chemically combined.
A pure substance that cannot be broken into a simpler substance is called what?
An element
Each element contains one kind of atom and has its own chemical properties.
Which subatomic particle has a -1 charge and moves outside the nucleus?
An electron
Electrons carry negative charge and occupy energy levels around the nucleus.
How many electrons fill the first, second, and third energy levels in our class model?
2, 8, 8
For our introductory model, the first shell holds 2 and the next two fill at 8.
In which type of bond do atoms share electrons?
A covalent bond
Shared electrons attract both nuclei and hold the atoms together.
NaCl contains sodium and chlorine, two different elements chemically combined.
Two or more atoms held together by covalent bonds
Examples include O₂, H₂O, and CO₂.
What is the smallest part of oxygen that still has all of carbon's chemical properties?
a oxygen atom
An atom is the smallest unit of an element that keeps that element's properties.
A neutral atom has atomic number 76. How many protons and electrons does it have?
76 protons and 76 electrons?
A neutral atom has equal numbers of positive protons and negative electrons.
Chlorine has 7 valence electrons. How many more does it need for a full outer shell?
1 electron
Chlorine usually gains one electron, which gives it a -1 charge.
Sodium is a metal and chlorine is a nonmetal. What type of bond forms in NaCl?
Ionic bond
Sodium transfers one electron to chlorine, forming Na⁺ and Cl⁻.
Is O₂ a molecule, a compound, both, or neither? Explain.
O₂ is a molecule, but it is not a compound.
Its oxygen atoms share electrons, but it contains only one element.
Name the six elements that make up most biological molecules.
CHONPS
An atom has mass number 40 and atomic number 20. How many neutrons does it have?
20 neutrons
Atomic number 20 means 20 protons. Then 40 - 20 = 20 neutrons.
Which class example is least likely to react because its outer energy level is already full?
What is neon, Ne?
Neon already has a full outer shell, so it is very stable.
Complete the pattern: losing an electron makes an atom ____. Gaining an electron makes an atom ____.
positive and negative?
After transfer, opposite charges attract and hold the ionic compound together.
Is H₂O a molecule, a compound, both, or neither? Explain.
Bonds break and form as the same atoms rearrange into new products.
The atoms keep their identities. Their connections change, producing substances with new structures.
Why can sodium metal react dangerously with water while sodium in a sports drink is safe?
The metal contains neutral Na atoms, while the drink contains Na⁺ ions.
A sodium ion has lost one electron. Its charge and chemical behavior differ from neutral sodium metal.
Two carbon atoms both have 6 protons, but one has 6 neutrons and the other has 8. What are they called?
Isotopes of Carbon
Isotopes have the same number of protons but different numbers of neutrons.
A neutral sodium atom has 11 electrons. Arrange them by shell, then predict what sodium usually does when bonding.
2-8-1, then sodium loses 1 electron?
Losing its one valence electron gives sodium a full outer level and forms Na⁺.
Compare NaCl and H₂O. What happens to electrons in each substance?
NaCl transfers electrons. H₂O shares electrons.
NaCl contains an ionic bond. The O-H bonds in water are covalent.
A neutral sodium atom has 11 protons and 11 electrons. It loses one electron to chlorine. State sodium's new proton count, electron count, charge, and the bond type that forms.
11 protons, 10 electrons, +1 charge
What is an ionic bond?
Sodium loses one negative electron, so the proton count stays the same while the net charge becomes +1. The transfer creates Na⁺ and Cl⁻, and their opposite charges attract.