Chemistry Quiz - Dr. Brennan Biology Honors

Matter

Solid, Liquid, and Gas

Element

a substance that cannot be broken down to other substances

How many elements does life require?

25 essential elements

Elements in the Human Body

Oxygen, Carbon, Hydrogen, Nitrogen

Atom

The smallest unit of matter that still retains the properties of an element

Proton

has a single positive electrical charge

Electron

has a single negative electrical charge

Neutron

is electrically neutral

Atomic Number

the number of protons in an atom

Mass Number

The sum of the number of protons and neutrons

Electrons

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What is another term for the outermost shell?

The Valance Shell

How many electron shells are in an atom?

1-3 shells per atom

What does the number of electrons in the outermost shell determine?

It determines the chemical properties of the atom.

How many electrons does the first shell hold?

Two electrons

How many electrons does the 2nd shell and valance shell hold?

Up to 8 electrons

Solve

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Find Sodium's Protons, Electrons, and Neutrons

Refer to Silde 14 on Chemistry #1 Slideshow

Find Oxygen's Protons, Electrons, and Neutrons

Refer to Slide 17 on Chemistry #1 Slideshow

Find Chlorine's Protons, Electrons, and Neutrons

Refer to Slide 18 on Chemistry #1 Slideshow

Isotopes

Atoms of the same element with a different mass, but same atomic number.

Compound

A substance consisting of two or more different elements combined in a fixed ratio.

Chemistry Slides 2

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Ion

An atom that has a negative or positive charge because of unequal amounts of protons and electrons.

Cation

A positively charged ion because it lost electrons

Anion

A negatively charged ion because it gained electrons

Chemical Bonds

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Why do chemical bonds form?

Atoms want to fill their valence shells.

Ionic Bond

the attraction between two oppositely charged ions

Covalent Bonds (Polar)

unequal sharing of electrons between atoms
- electronegativity
- More electronegative atoms pull harder

Covalent Bonds (Nonpolar)

an equal sharing of electrons between atoms
-between two atoms of the same element
-between carbon and hydrogen

What element is positive and what element is negative in water?

Oxygen is negative
Hydrogen is positive

Characteristics of a Hydrogen Bond

- weakest bonds
-can not form a compound

Why is it called a hydrogen bond?

The positively charged region is always a hydrogen atom