Alkali metals: left column of your periodic table (not hydrogen, but anything below it). They have one valence electron, which they are happy to share in a reaction.
Halogens: second column from the right of your periodic table. They are one electron short of a full shell, so they are reactive in the opposite way that alkalis are--they want electrons.
Atomic number (number of protons) is the big number on the periodic table square. Hydrogen's is 1.
Atomic mass is a little number down below. For example, Hydrogen's is 1.008.
Neutrons are a tricky subject, because different isotopes of the same element can have different numbers of neutrons. You can't generally get this from the atomic mass, because the atomic mass is a weighted average of naturally occurring isotopes. Hydrogen can have 0,1, or 2 neutrons. To answer this, you'd have to choose a particular isotope from the table of isotopes (a completely different chart from the periodic table) which has a certain number of neutrons: n = weight - Z.
Valence electrons are the electrons in the outermost shell. (The column of the table).
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Number of principal shells is the row of the periodic table. </span>
Should be an air tight seal
Answer:
1. 610,000 lb ft
2. 490 J
Explanation:
1. First, convert mi/hr to ft/s:
100 mi/hr × (5280 ft / mi) × (1 hr / 3600 s) = 146.67 ft/s
Now find the kinetic energy:
KE = ½ mv²
KE = ½ (1825 lb / 32.2 ft/s²) (146.67 ft/s)²
KE = 610,000 lb ft
2. KE = ½ mv²
KE = ½ (5 kg) (14 m/s)²
KE = 490 J
Aswer:
False, the values of the distance traveled and the displacement only coincide when the trayectorie is a straight line. Otherwise, the distance will always be greater than the offset.
Although these terms are used synonymously in other cases, they are totally different. Since the distance that a mobile travels is the equivalent of the length of its trajectory. Whereas, the displacement will be a vector magnitude.
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