Elements
Elements are made of Atoms
Electrons in Energy Levels
Isotopes
What Elements are Most Abundant?
100
O is the chemical symbol for what element?
Oxygen
100
What particle has about the same mass as a proton but is electrically neutral?
A neutron
100
Which energy level can hold up to 32 Electrons?
The fourth energy level
100
Many elements are mixtures of ________.
Isotopes
100
True or False: Rocks can contain Oxygen.
True
200
C is the chemical symbol for what element?
Carbon
200
What particle of mass has a positive electric charge?
Proton
200
Elements that do not easily combine with other elements are called ______?
Inert
200
The element chlorine has ____ isotopes.
2
200
Scientists have identified the two most abundant elements in the universe as _______ and ________
Hydrogen and helium
300
What is a substance that can not be broken down into simpler means by physical or chemical means?
Elements
300
What is the smallest particle of an element that has all of the characteristics of an element.
An Atom
300
What are the electrons in the outermost energy level called?
Valence Electrons
300
What is the prossces called when the nuclei of an isotope release radiation?
Radio Activity
300
What 2 elements account for almost 75% of the Earths crust
oxygen and silicon
400
What is the chemical symbol for gold?
Au
400
What part of a atom is made up or protons and neutrons
Nucleus
400
The number of electrons in the outermost energy level determines the ________ behavior of the different elements.
Chemical
400
When atoms of the same element have different mass numbers, they are known as _________.
Isotopes
400
Oxygen is a _______ element mostly found in chemical combinations with other elements.
Reactive
500
How many elements occur naturally on Earth and the stars?
92
500
What is the number of protons and neutrons in an atoms nucleus?
Atomic Number
500
Electrons tend to occupy the _______ available energy level.
Lowest
500
What is the average of the mass numbers of the isotopes of an element?
Atomic Mass
500
How many elements make up 98.5% of the Earth's
8
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