Answer:5
Explanation:The pnictogen group, or nitrogen group, is located in column 15 of the periodic table. This family consists of the elements nitrogen, phosphorus, arsenic, antimony, bismuth, and ununpentium (N, P, As, Sb, Bi, and Uup, respectively). Each member of this family contains five valence electrons.
BIOLOGICAL & CHEMICAL EVIDENCE ANALYSIS
There are many different types of evidence that can be found at a crime scene. Physical evidence can be collected at the crime scene such as a murder weapon. Chemical evidence is any residue from liquids that such as poison and drugs. Biological evidence is when hair or skin from a persons body has been transferred to a physical surface and then be collected and tested.
This evidence can be used to find out what exactly happened at the scene of the crime, the history behind the crime and who was involved and could have committed it.
Our experts test and analyse many forms of evidence, which is vital when finding out the various incidences that happened at a crime scene.
<span>the molar mass of a compound is the sum of the products of the atomic masses by the number of atoms of the element.
molar mass of Na</span>₂SO₄<span> is - 142 g/mol.
1 mol of </span>Na₂SO₄<span> has a mass of 142 g.
In 1 mol of </span>Na₂SO₄<span> the mass of Na is 23 g/mol x 2 = 46 g.
Mass of Na in 1 mol of </span>Na₂SO₄ is - 46 g
mass of Na in 0.820 mol of Na₂SO₄ - 46 g /1 mol x 0.820 mol = 37.72 g.
mass of Na is 37.72 g
Answer:
Aromatic Hydrocarbons
Explanation:
Aromatic (Pleasant Odour) Hydrocarbons are those having pleasant odours.
Each type of
mineral has a chemical composition that is unique such as its chemical composition
and the arrangement of atoms. For example, the mineral hematite is Fe2O3. There
are two atoms of iron (Fe) and three atoms of oxygen (O).
