Answer:
D. They have the same number of protons as electrons.
Explanation:
Protons are found in the nucleus of the atom and have a positive charge while electrons orbit around the nucleus and have a negative charge. Usually, in a neutral atom of an element, the number of protons is equal to the number of electrons. This is why the atom has no charge because the positive and negative charges cancel out. When an atom loses an electron its charge turns positive while when it gains an electron its charge turns negative.
The percent of O in Cr₂O₃ : 31.58%
<h3>Further explanation</h3>
Given
Cr = 52.00 amu, O = 16.00 amu
Required
The percent of O
Solution
MW Cr₂O₃ = 2 x Ar Cr + 3 x Ar O
MW Cr₂O₃ = 2.52+3.16
MW Cr₂O₃ =152 amu

Answer:
Chlorowanie wody jest procesem względnie tanim – koszt zbudowania samej instalacji do dezynfekcji, jak również koszt operacyjny wytworzenia 1 metra sześciennego uzdatnionej chlorem wody jest niższy od dezynfekcji wody za pomocą ozonu. Źródłem chloru w procesie dezynfekcji jest zazwyczaj podchloryn sodu, rzadziej dwutlenek chloru.
Explanation:
The brain. The brain tells the body what to do same way the nucleus does for the cell.