Chapter 2-Energy And Matter Flashcards
Which particles form the nucleus of an atom?
Protons and neutrons
Positively charged particles
Protons
Negatively charged protons
Electrons
Neutrally charged particles
Neutrons
What does the atomic number represent?
The number of protons and electrons
How do you find the number of neutrons in an atom?
Subtract the atomic number from the atomic weight
What distinguishes one atom from another?
The number of protons
What gives an atom it’s certain properties?
The number of electrons
How many electrons can be held in the first energy level?
2 electrons
How many electrons can be held in the outermost layer?
8 electrons
How many electrons are held in the outermost layer in a carbon atom?
4 electrons
How many elements are found on earth?
91 elements
How many elements are found in organisms?
25 elements
A substance made of atoms of different elements bonded together in a certain ratio
Compound
An atom that has gained or lost one or more electrons to other atoms
Ion
What charge does an ion gain when it loses one or more electrons?
Positive
What charge does on ion gain when it gains one or more electrons?
Negative
Bonds formed through the electrical force between oppositely charged ions
Ionic bond
Bond formed when atoms share a pair of electrons
Covalent bond
Two or more atoms held together by covalent bonds
Molecule
Has a region with a slight positive change and a region with a slight negative charge
Polar molecule
An attraction between a slightly positive charged hydrogen atom and a slightly negatively charged atom
Hydrogen bond
What are the three properties given from hydrogen bonds?
High specific heat, cohesion, and adhesion
Property that means water resists changes in temperature?
High specific heat
The attraction among molecules of a substance, makes water molecules stick to other water molecules, creates surface tension
Cohesion
The attraction among water molecules to different molecules
Adhesion
What causes hydrogen bonds to form between polar molecules?
Polar molecules have partially charged regions that attract other polar molecules
What must happen for molecules and ions to take part in chemical processes inside cells?
They must dissolve in water
How is a solution made?
When one substance dissolves in the water in your body or other substances
A mixture of substances that is the same throughout
Solution
The substance that is present in the grater amount and the part that dissolves the other substances
Solvent
A substance that dissolves in a solvent
Solute