HELP ASAP Calculate the atomic mass of each of the following elements using your method from above. Test your answer using the Nature’s mix of isotopes and the periodic table. SHOW ALL WORK as we have been doing for these problems. Silicon: Isotope 1 - mass 27.97 amu, 92.22% abundance Isotope 2 - mass 28.9764 amu, 4.685 % abundance Isotope 3 - mass 29.97377 amu, 3.092% abundance

Classify this reaction: 2al+n2-> aln.

Astable electron arrangement for an atom is one that does not easily change. how is this arrangement arrived at? a. valence electrons are transferred or shared to create a full outer shell of electrons. b. valence electrons are discarded into space to create a full outer shell of electrons. c. protons (positive charge) pair with valence electrons (negative charge) to create a strong bond. d. outer shells with valence electrons are transferred or shared.

Which of these is an example of pseudoscience? a) predicting the time of sunrise based on data on position of earth b) predicting the date of the moon phases based on data on position of earth c) predicting eclipses based on the position of the sun and the moon d) predicting future events in a person's life based on the position of the moon