Elements
These have the same number of valence electrons.
What are groups?
This is the group number and name for the most stable elements.
What is 18/ noble gasses?
This is the periodic table.
What does the atomic number organize?
These are changes that form new substances and cannot be undone.
What are chemical changes?
To find the atomic mass.
Why would you add protons and neutrons?
What is the number of protons of an element?
What is atomic number?
protons + neutrons
What is atomic mass?
2 electrons
How many electrons on the 1st energy level?
What are the smallest unit of an element that maintains the properties of that element?
What are atoms?
Atomic number and # electrons
What equals the number of protons? (2 things)
Find the atomic mass of Selenium.
What is 79.0?
This is the number of valence electrons in energy levels 2, 3, (and 4 optional)
Alt: the max number of electrons in levels 2, 3, (4)
What is 8 valence electrons?
These are elements that have properties of metals and nonmetals.
What is a metalloid?
The nucleus of an atom.
What is positively charged and contains protons & neutrons?
2-8-8
How many electrons in the 1st, 2ns & 3rd energy levels?
Any noble gas.
What is 8 valence electrons?
2 elements
How many elements in 3NaCl?
What charges do electrons, protons, and neutrons have?
What is electrons have a negative charge, protons have a positive charge, and neutrons have no charge?
Group 1
What group is the most reactive metal?
Valence electron for any element in group 1. Also group 1.
What is 1 valence electron?