perfomance and size
The * selector is used to match any element in the hierarchy.
Every element has a different number of protons and electrons in each atom, and this amount is what the atomic number tells you.
D smallest element in data hierarchy is FIELD.REASON: It (field) is d smallest bit of information found in a record.
they can distinguish one element from another becasue by the protons and the nuetrons , they can over come almost anything.
The mass number of an isotope tells you the total number of protons and neutrons in the nucleus of that atom. It is used to distinguish different isotopes of an element, as isotopes of the same element have the same number of protons but different numbers of neutrons.
Contextual selectors
By the number of protons
Many chemical elements have a two letter symbol.
The atomic number is the number of protons in an atom, and each element has a unique atomic number. This means that the atomic number is used to identify and distinguish one element from another. The number of protons in an atom determines its chemical properties and its placement on the periodic table.
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The unique number of protons in the nucleus of an atom is an element's atomic number. This identifies an element.
The unique number of protons in the nucleus of an atom is an element's atomic number. This identifies an element.