How many neutrons are found in an atom of aluminum–27?

Match term definition ellipse a) diagonal cross section of a cylinder circle b) diagonal cross section through the widest part of a sphere sphere c) cross section parallel to the base of a cone great circle d) shape created when a semi-circle is rotated around the y-axis triangle e) perpendicular cross section of a cone

According to periodic trend, which of the following most likely has the highest ionization energy? kr be ni sc

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.