The periodic table is based on an element's what

Answer is: atomic number.

Elements are scheduled in periodic table, ordered by their atomic number.

Atomic number (Z) is the number of protons (p⁺), which is characteristic of a chemical element.

There are 118 unique substances (elements) arranged on an amazing chart that reveals their hidden secrets to anyone who knows how to read it.  

The first chemical element is hydrogen (atomic number is 1) and the last is oganesson (atomic number is 118).  

First element on the periodic table is hydrogen (H) with atomic number 1, after hydrogen is helium (He) with atomic number 2, than lithium (Li) with atomic number 3 and so on until atomic number 118.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

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