término  |
definición |
|
empezar lección
|
|
Tiny particles that make up all elements and substances
|
|
|
What is the structure of an atom? empezar lección
|
|
A central nucleus containing protons and neutrons, surrounded by electrons in shells
|
|
|
Which particles are found in the nucleus? empezar lección
|
|
|
|
|
Where are electrons found? empezar lección
|
|
In the shells around the nucleus
|
|
|
What is the relative mass of a proton & neutron? empezar lección
|
|
|
|
|
What is the relative mass of an electron? empezar lección
|
|
|
|
|
|
empezar lección
|
|
Because the number of protons equals the number of electrons
|
|
|
|
empezar lección
|
|
A charged particle formed when an atom gains or loses electrons
|
|
|
What happens when an atom loses electrons? empezar lección
|
|
It becomes a positive ion
|
|
|
What happens when an atom gains electrons? empezar lección
|
|
It becomes a negative ion
|
|
|
What is the atomic number? empezar lección
|
|
The number of protons in an atom
|
|
|
What does the atomic number tell you? empezar lección
|
|
|
|
|
|
empezar lección
|
|
The total number of protons and neutrons
|
|
|
How do you calculate neutrons empezar lección
|
|
Number of neutrons = mass number - atomic number
|
|
|
|
empezar lección
|
|
Atoms of the same element with the same number of protons but a different number of neutrons
|
|
|
Why do isotopes have different masses? empezar lección
|
|
Because they contain different numbers of neutrons
|
|
|
Why do isotopes react the same chemically? empezar lección
|
|
Because they have the same number of electrons
|
|
|
What is relative atomic mass? empezar lección
|
|
The average mass of all the isotopes of an element
|
|
|
How is relative atomic mass calculated? empezar lección
|
|
Sum of (isotope abundance x isotope mass) / total abundance
|
|
|
What is an electron configuration? empezar lección
|
|
The arrangement of electrons in shells around the nucleus
|
|
|
Why are full outer shells important? empezar lección
|
|
Atoms are more stable when their outer shell is full
|
|
|
Why are noble gases unreactive? empezar lección
|
|
They already have full outer electron shells
|
|
|
What ion does sodium form? empezar lección
|
|
Na+ because it loses 1 electron
|
|
|
What ion does fluorine form? empezar lección
|
|
F- because it gains 1 electron
|
|
|
What ion does calcium form? empezar lección
|
|
Ca2+ because it loses 2 electrons
|
|
|
