Scientific Method & Measurements
What is purposefully being manipulated and changed in an experiment is the _____.
independent variable
Identity of an element depends on…
Protons
The force that overcomes proton–proton repulsion is the…
strong nuclear force
How many valence electrons does magnesium typically have?
2
[Ar]4s²3d¹⁰4p³ corresponds to…
As
You are conducting an experiment and find the volume of a substance to be 4.52 mL. If the known volume of the substance is 4.99 mL, find the percentage error in your measurement.
(4.52−4.99)/4.99×100=9.42
Answer: 9.42%
true or false: the nucleus contains nearly all the volume
false
Which subatomic particle would NOT be found in the nucleus?
electrons
How many valence electrons does aluminum have?
3
Anions have ___ electrons and are ___ charged.
gained; negative
true or false: A chemical change results in a change in energy AND a change in the amount of matter.
true
what is the Atomic number of this atom: (5p, 6n, 8e)
5
Boron isotopes: 10.01 and 11.01. Which is more abundant?
11.01
The number of energy levels in an atom depends on the number of…
electrons
Cations have ___ electrons and are ___ charged.
lost; positive
Significant figures in 906 mmHg
3 sig figs
An atom is electrically neutral when…
protons = electrons
Valence electrons in this configuration: 1s²2s²2p⁶3s²3p³
Significant figures in 0.0051 mL
51 → 2 sig figs
The force between nucleus & electrons is ___; between electrons is ___.
attractive; repulsive
Number of energy levels in this configuration: 1s²2s²2p⁶3s²3p³
3