All categories

2 years ago

Correct way for calculating atomic mass

Chemistry

1 answer:

kolezko [41]2 years ago

5 0

Answer:

mass number = protons + neutrons.

Explanation:

Together, the number of protons and the number of neutrons determine an element's mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

You might be interested in

Question 4

vazorg [7]

Answer:

H(aq) + NO3 (aq) + HF(aq)

Explanation:

In the given mixture of HNO3 (Nitric Acid) and HF (hydrofluoric acid) in water the major species present are H(aq) + NO3 (aq) + HF(aq).

On the reaction of HNO3 (Nitric Acid) and HF (hydrofluoric acid) in water , it will give a polar solution and will form a homogenous mixture.

Hence, the correct answer is "H(aq) + NO3 (aq) + HF(aq)".

4 0

2 years ago

The Nutrition Facts label for crackers states that one serving contains 19 g of carbohydrate, 4 g of fat, and 2 g of protein. Wh

sp2606 [1]

<u>Answer:</u> The amount of kilocalories contained in the given serving of crackes is 0.120 kCal

<u>Explanation:</u>

Carbohydrates provide 4 calories per gram, protein provides 4 calories per gram, and fat provides 9 calories per gram

We are given:

Mass of fat in the crackers = 4 g

Mass of carbohydrates in the crackers = 19 g

Mass of protein in the crackers = 2 g

Conversion factor used: 1 kCal = 1000 Cal

Applying unitary method:

<u>For Fat:</u>

1 gram of fat provides 9 calories

So, 4 gram of fat will provide = $\frac{9}{1}\times 4=36Cal=0.036kCal$

<u>For Carbohydrates:</u>

1 gram of carbohydrates provides 4 calories

So, 19 gram of carbohydrates will provide = $\frac{4}{1}\times 19=76Cal=0.076kCal$

<u>For Proteins:</u>

1 gram of proteins provides 4 calories

So, 2 gram of fat will provide = $\frac{4}{1}\times 2=8Cal=0.008kCal$

Total kilocalories per serving = [0.036 + 0.076 + 0.008] kCal = 0.120 kCal

Hence, the amount of kilocalories contained in the given serving of crackes is 0.120 kCal

8 0

3 years ago

Why is it impossible to ever prove that a hypothesis is true?

maria [59]

Answer: A

Explanation:

Hypothesis have to be based on previous knowledge and have to be able to be tested but the problem is most hypothesis can’t be explained so it’s impossible to prove a hypothesis correct because science uses inductive reasoning

4 0

3 years ago

2. Which of the following is true about the total number of reactants and the total number of

Soloha48 [4]

9 moles of reactants chemically change into 11 moles of product.

Explanation:

In the reaction above, 9 moles of reactants chemically change into 11 mole of products. The coefficients in a reaction is the number of moles of the reacting atoms .

For example 8O₂ depicts 8 moles of two oxygen atoms.
The number of moles is a unit for quantifying particles.
You can liken it to a dozen, gross or a score.
Since a mole of a substance contains avogadro number of particles. We can relate the number of moles to other parameters.

Learn more:

Moles brainly.com/question/2272966

#learnwithBrainly

8 0

2 years ago

Read 2 more answers

The following compound has been found effective in treating pain and inflammation (J. Med Chem. 2007, 4222). Which sequence corr

love history [14]

<h3><u>Full Question:</u></h3>

The following compound has been found effective in treating pain and inflammation (J. Med. Chem. 2007, 4222). Which sequence correctly ranks each carbonyl group in order of increasing reactivity toward nucleophilic addition?

A) 1 < 2 < 3

B) 2 < 3 < 1

C) 3 < 1 < 2

D) 1 < 3 < 2

<h3><u>Answer: </u></h3>

The rate of nucleophilic attack of carbonyl compounds is 2<3 <1.

Option B

<h3><u>Explanation. </u></h3>

Nucleophilic attack is explained as the attack of an electron rich radical to a carbonyl compound like aldehyde or a ketone. A nucleophile has a high electron density, so it searches for a electropositive atom where it can donate a portion of its electron density and become stable.

A carbonyl compound is a $sp^2$ hybridized carbon atom with a double bonded oxygen atom in it. The oxygen atom pulls a huge portion of electron density from carbon being very electropositive.

In a ketone, there are two factors that make it less likely to undergo a nucleophilic attack than aldehyde. Firstly, the steric hindrance of two carbon groups being attached with the carbonyl carbon makes it harder for the nucleophile to approach. Secondly, the electron push by the carbon groups attached makes the carbonyl carbon a bit less electropositive than the aldehyde one. So aldehydes are more reactive towards a nucleophilic addition reaction.

7 0

3 years ago