All categories

3 years ago

The mass number of an element is equal to ____.

Chemistry

2 answers:

melisa1 [442]3 years ago

4 0

Mass number is the total number of protons and neutrons in the nucleus

nlexa [21]3 years ago

3 0

Answer: b. the total number of protons and neutrons in the nucleus

Explanation:

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons

Thus the mass number of an element is equal to the total number of protons and neutrons in the nucleus.

You might be interested in

calculate the atomic mass of element X, if it has 2 naturally occurring isotopes with the following masses and natural abundance

jeka57 [31]

Hey there!

To find this, you should:

1) multiply the percentage (but in a decimal form) of each isotope by the mass.
2) add all your masses together
3) make sure to check for significant figures and you’re done!

Hope this helps :)

4 0

3 years ago

Using the curve which letter represents efficiency?

velikii [3]

Answer:

point A , B and C

Explanation:

The efficient frontier is the set of optimal portfolios that offer the highest expected return for a defined level of risk or the lowest risk for a given level of expected return

4 0

2 years ago

a helium balloon has a volume of 2.95 liters at 25 c. the volume of the ballon decreased to 2.25 l after it is placed outside on

OleMash [197]

Answer:

The outside temperature is -45.8°C

Explanation:

When a gas keeps on constant its moles and its pressure, we can assume that volume will be increased or decreased as the T° (absolute T° in K).

V1 / T1 = V2 / T2

2.95L/298K = 2.25L / T2

(2.95L/298K ) . T2 = 2.25L

T2 = 2.25L . 298K / 2.95L

T2 = 227.2K

T°K - 273 = T°C

227.2K - 273 = -45.8°C

3 0

3 years ago

What type of animal might become preserved in amber

goldfiish [28.3K]

Insect's or Bugs preserved in Amber

6 0

3 years ago

Which shows the rational expression written using the least common denominator?

Alexandra [31]

Answer:

The first one.

$\frac{x + 1}{4x^{2} } and \frac{4(x + 1)}{4x^{2} }$

Explanation:

When comparing two fractions with variables like this, it's important to get to the same denominator in order to compare apples with apples and then be able to do not only comparisons but also perform additions/subtractions.

Question is which denominator to use and how to reach it.

In this case, the question and the answer choices do the work for you. The question asks which one is the LEAST common denominator, and the answers show denominators x² and 4x². The smallest of these is x², however, we can't simplify the first fraction to get to the x² denominator, so we'll go for the 4x².

So, the first fraction has already the correct denominator (4x²), we just have to transform the second one.

We multiply it by 1, expressed in a different way. Since we're multiplying by one, we're not affecting the value, just the way it looks.

Let's do it!, to get the denominator to go from x² to 4x², we need to multiply it by 4... so we'll multiply by 4/4 (which is 1, neutral for the multiplication).

$\frac{x + 1}{x^{2} } * \frac{4}{4} = \frac{4(x + 1)}{4x^{2} }$

And now you have both fractions on the same denominator, without having changed their value, just their looks

6 0

3 years ago