Answer: two or more different pure substances, which may be elements or compounds.
Explanation:
The term varieties of matter is kind of ambiguos since it is not defined.
The best approach to the question is to think of matter as it can be classified into to kinds: pure substaces and mixtures.
Elements and compounds are pure substances.
Elements are pure substances constituted by only one kind of atoms. An element cannot be divided into simpler substances either by physical or chemical media.
A compound is a chemical combination of two or more different elements. A compound can be divided into simpler substances by chemical reactions, but not by physical media. The properties of compounds are different of those of the elements of which they are constituted. The composition of a compoind (ratio among its elements) is fixed.
A mixture is the physical combination of two or more pure substances (either different elements or compounds) which can be mixed in any proportion. This is, its composition is variable. The substances that form the mixture can be separated by physical media.
Answer:
The vertical columns (group) of the periodic table are arranged such that all it's elements have the same number of valence electrons. All elements within a certain group thus group share similar properties.
Answer:
See explanation
Explanation:
The formal charge is obtained from;
Formal Charge = Valence electrons on atom - [number of bonds - lone pair electrons]
The correct structure of ClF2+ is the structure attached to this answer (image obtained from quora) in which the formal charge on fluorine is zero and the formal charge on chlorine is + 1. This is the correct structure because the chlorine is more electronegative than fluorine as expected.
An atom is the simplest particle that exists and retains the property of the element. A compound is made up of two or more elements chemically combined.
In an average mass, each entry has equal weight. In a weighted average, we multiply each entry by a number representing its relative importance.
Assume that your class consists of 15 girls and 5 boys. Each girl has a mass of 54 kg, and each boy has a mass of 62 kg.
<em>Average mass</em> = (girl + boy)/2 = (54 kg + 62 kg)/2 = <em>58 kg</em>
<em>Weighted average (Method 1)
</em>
Use the <em>numbers of each</em> gender (15 girls + 5 boys)
,
Weighted average = (15×54 kg + 5×62 kg)/20 = (810 kg + 310 kg)/20
= 1120 kg/20 = <em>56 kg</em>.
If you put all the students on one giant balance, their total mass would be
1120 kg and the average mass of a student would be <em>56 kg.
</em>
<em>Weighted average (Method 2)
</em>
Use the <em>relative percentages</em> of each gender (75 % girls and 25 % boys).
Weighted average = 0.75×54 kg + 0.25×62 kg = 40.5 kg + 15.5 kg = <em>56 kg</em>
Each girl contributes 40.5 kg and each boy contributes 15.5 kg to the <em>weighted average</em> mass of a student.
