CHEMISTRY HIGH SCHOOL

Does anyone know where i can find a practice cumulative chem test online?

Answers

Answer 1
Answer: exam board websites often have past papers from several previous years, if you know what exam board you are going to be using, try that, if not there may be content on the edexcel and AQA websites

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Ozone is dangerous to human health only when it is found in the what?

Answers

Only when it is found in the atmosphere, because it will create a hole, letting strong UV rays shine down on earth, heating it up, and causing skin cancer in humans and other animals.

Answer:

A) Stratosphere

B) trosphere

C)mesosphere

D)thermosphere

Explanation:

D) thermosphere

The lewis structure of n2h2 shows __________.a.a nitrogen-nitrogen triple bond
b.a nitrogen-nitrogen single bond
c.each nitrogen has one nonbinding electron pair
d.each nitrogen has two nonbinding electron pairs
e.each hydrogen has one nonbonding electron pair

Answers

The Lewis structure of Diimide (N₂H₂) is shown below.

In this molecule two Nitrogen atoms attached to each other through a double bond are further attached to one one Hydrogen atom. Also, each Nitrogen atom carries one non-binding electron pair (Lone Pair) (Highlighted RED).

Result:
          Option-C (each nitrogen has one nonbinding electron pair) is the correct answer.

The lewis structure of n2h2 shows

c. each nitrogen has one nonbinding electron pair

Lewis structures are diagrams that show the bonds between the atoms of a molecule and the lone pair of electrons that might exist in a molecule.

Further Explanation

Lewis structures can be drawn for each covalently bonded molecule, as well as coordination compounds. The Lewis structure is named after Gilbert N. Lewis, who introduced in his 1916 article The Atom and the Molecule. The Lewis structure extends the concept of the electron point diagram by adding lines between atoms to represent pairs together in chemical bonds.

The Lewis structure shows each atom and its position in the molecular structure using its chemical symbol. Lines are drawn between atoms that are bound to one another (pairs of dots can be used instead of lines). The excess electrons that make up lonely pairs are represented as pairs of points and are placed next to the atom.

The number of electrons represented in the Lewis structure is equal to the number of valence electrons in each atom. Non-valence electrons are not represented in the Lewis structure.

In the case of Lewis structures, formal charges are used in the description, comparison, and assessment of the topological and resonant structures that might occur by determining the apparent electron charge of each atom, based on the structure of the electron points, assuming exclusive covalence or non-polar bonds. Formal charges have been used in determining possible electron reconfigurations when referring to reaction mechanisms, and often produce the same sign as the partial charge of atoms, with the exception.

Learn More

Lewis structures brainly.com/question/9736616

Atom/Electron brainly.com/question/9736616

Details

Class: High School

Subject: Chemistry

Keyword: lewis, Structure, electron

At normal temperature and pressure, air has a density of 0.001184 g/mL. What is the mass of air in a room that is 3.07 m by 3.00 m by 3.77 m? Answer in units of kg.

Answers

1 ml = 1 cm3
The volume of the room is 34.7217 m3 or 34.721.700 cm3, so 34.721.700 * 0.001184 g/cm3= 41,1104928 kg.

Which element is present in all organiccompounds?
(1) nitrogen
(2) oxygen
(3) carbon
(4) sulfur

Answers

i'm pretty sure hydrogen is but i would go with #3 carbon

What would happen if you play a note in a cold day on a flute?

Answers

I don't know if this is the answer you are looking for but it would be flat unless the player pushed the tuning slide in.

What is the mass percent of nitrogen in ammonium carbonate, (NH4)2CO3?

Answers

In order for you to calculate for the mass of ammonium carbonate, you need to know the molar mass of it and the nitrogen atoms in the compound. Ammonium carbonate has a molar mass of 96.08 grams per mole. There are two nitrogen atoms in ammonium carbonate which is equal to 28.02 grams per mole. Divide the molar mass of nitrogen to the ammonium carbonate, 28.02/96.08 x 100, we get 29.16wt% nitrogen.

Answer:

29.16%.

Explanation:

You can determine the mass percent, or how much of the total mass of ammonium carbonate is nitrogen, by first determining the mass of nitrogen and the mass of the total compound.

1. the mass of nitrogen in this compound is 2 x 14.007, or 28.014.

2. the mass of ammonium carbonate is 96.09 grams.

To find the percentage of nitrogen in the overall mass of ammonium carbonate, simply divide the mass of nitrogen by the mass of ammonium carbonate and multiply by 100:

28.014/96.09 x 100 ....................... 29.16%.

Also, I got the correct answer :)
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