Answer:
(1)There are 1.5 moles of water in a 27 gram sample of water. The molar mass of water is 18.02 gmol g m o l .(2)
AnswersChemistryGCSEArticle
What is the mass (g) of 0.25mols of NaCl?
What you need for these equations are a calculator, periodic table and the following equation:
Mass (g) = Mr x Moles (important equation to remember)
In this case we already know the moles as it's in the question, 0.25 moles.
to find the Mr, you need to look at your periodic table. Find the relative atomic mass of Na and Cl and add the two numbers together.
Na = 22.99
Cl = 35.45
NaCl = 58.4
Now just put all of the numbers into the equation.
0.25 x 58.4 = 14.6g
Answer:
D.
Explanation:
It would not be gain because it would say +6 instead of -2. Having a -2 charge means it wants to loose 2 electrons so it can form a full shell of 8 electrons. It wants to be inert (stable).
- Hope that helps! Please let me know if you need further explanation.
Answer:
Elements that belong to the <em>same </em><em>GROUP</em><em> </em>of the periodic table have the most similar chemical properties.
Explanation:
A GROUP in the periodic table is a column of elements with the same number of valence electrons. Since electrons are exchanged/shared during a chemical reaction, then elements with similar valence electrons, will react similarly. Thus elements belonging to the <em>same GROUP</em> are most similar in the way they react.
For example: Sodium and Lithium are group 1 elements while fluorine and chlorine are group 17 elements. In a reaction under normal conditions, Sodium and Lithium will both try to give up their single valence electron to form cations. In doing so they will react more similarly. On the other hand, Fluorine and Chlorine who are more inclined to accept a single electron to form cations react less like the group 1 elements and more like each other.
Answer:
A- Physical, B- Chemical, C- chemical, D- Physical
Explanation:
A is physical because you can see it changing its form is changing.
B is Chemical because a new substance is formed creating the orange color of rust.
C is a Chemical reaction because it is being broken down so the banana itself is changing not just how we see it.
D is physical because we are just changing the shape/ size of the item, not anything to do with its substances.
Answer:
Compounds between Nonmetals and Nonmetals
Compounds that consist of a nonmetal bonded to a nonmetal are commonly known as Molecular Compounds, where the element with the positive oxidation state is written first. In many cases, nonmetals form more than one binary compound, so prefixes are used to distinguish them.
