Answer:
A. 39
Explanation:
Mass number= #protons + #neutrons
19+20= 39
Taking into account the definition of mass number, the correct option is the option A: the atomic mass of the atom is 39.
First of all, all atoms are made up of subatomic particles: protons and neutrons, which are part of their nucleus, and electrons, which revolve around them. Protons are positively charged, neutrons are neutrally charged, and electrons are negatively charged (electrons).
On the other hand, the mass number tells us the total number of particles in the nucleus. That is, the mass number is the sum of the number of protons and the number of neutrons in the atomic nucleus:
Mass number = (number of protons) + (number of neutrons)
It is represented by the letter A.
In this case:
number of protons= 19number of neutrons= 20So:
Mass number = 19 + 20
Solving:
Mass number= 39
In summary, the correct option is the option A: the atomic mass of the atom is 39.
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https://brainly.com/question/11837355?referrer=searchResultshttps://brainly.com/question/1758023A student wants to find the volume of a rock. the student starts with 25ml of water in their graduated cylinder that water level rises to 37ml. what is the volume of the rock?
Answer:
12 ml
Explanation:
the answer will be calculated by subtracting 37 ml from 25 ml so ,
37 - 25
= 12 ml
A 4.86 g piece of metal is placed in a graduated cylinder containing 15.5 mL of water the water level rose to 17.3 mL what is the density of the metal
Answer:
The answer is 2.70 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 4.86 g
volume = final volume of water - initial volume of water
volume = 17.3 - 15.5 = 1.8 mL
So we have
[tex]density = \frac{4.86}{1.80} \\ [/tex]
We have the final answer as
2.70 g/mLHope this helps you
Which of the following is the correct name for N2S5?
PLEASE ANSWER FAST
A model of an atom is shown above. The blue dots represent electrons, and the red dot represents the nucleus. This model accurately represents
A.
that electrons are found everywhere in an atom, even in the nucleus.
B.
what an atom would look like when seen through a microscope.
C.
that a single atom may have many nuclei.
D.
that the nucleus is located at the center of the atom.
Answer:
D. that the nucleus is located at the center of the atom
I hope that this helps!
There are several atomic models which explain the structure of atoms. Here the given model of atom is similar to Rutherford's model of atom. The nucleus is located at the center of the atom. The correct option is D.
What is Rutherford's atomic model?In Rutherford's atomic model, he bombarded a thin sheet of gold foil with high energy alpha particles and made several observations. He said that most of the space inside the atom is empty. A heavy positively charged body called nucleus is present inside the atom.
The nucleus is capable of repelling and deflecting highly energetic alpha particles and also has a appreciable mass and charge. The volume occupied by the heavy positively charged body must be very very small.
Here in the given model, blue dots are electrons which revolve around the nucleus and the red dot is the nucleus which is present at the centre.
Thus the correct option is D.
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What Element am I?
I have 5 Valence Electrons.
I am in the 5th row.
My atomic mass is less than Bismuth *
с
Answer:
Nitrogen
Explanation:
Nitrogen has 5 Valence Electrons.
And its atomic mass is also less than Bismuth.
There are other elements in the 5th row but this one has the lowest atomic mass compared to the others.
#11- i will mark 5 stars, thanks, and mark brainliest just please help me
Answer:
what is the question????
Which element has a greater atomic radius Mg or Cl?
How are hypotheses different from theories?
Answer:
Explanation:
This is the Difference Between a Hypothesis and a Theory. In scientific reasoning, a hypothesis is an assumption made before any research has been completed for the sake of testing. A theory on the other hand is a principle set to explain phenomena already supported by data.
many reactive chemicals are stored in containers filled with Argon gas for safekeeping what about Argon's atomic structure makes it safe to store reactive chemicals in?
Answer:
Argon has 8 valence electrons making it non reactive.
Explanation:
Reactive chemicals are store in containers filled with Argon gas because the argon gas is non reactive. This is true because the argon gas has completely filled octet structure.
This can further be explained by writing the electronic configuration of argon.
The electronic configuration of argon is given below:
Ar (18) => 1s² 2s²2p⁶ 3s²3p⁶
Valence electron => 3s²3p⁶ = 2 + 6 = 8
From the above illustration, we can see that the outermost shell (i.e 3s²3p⁶) is having 8 electrons indicating that it is completely filled as the maximum number of electrons any shell can accommodate outside the first shell is 8 electrons. Thus, argon has 8 valence electrons ( i.e electrons in the outermost shell) and hence it is non reactive as the outermost shell is completely filled.
Question 5 of 10
SO3 is an empirical formula for which of the following?
A. S04
B. S203
C. S402
D. S206
help me, please, i need it
Answer:
I think the answer would be C.
Explanation:
Microwaves emit radiation onto the leftover food, meaning the heat transfers to it through radiation.
7. If we have the same number of protons and electrons, our atom is ___________________________.
A: Negative
B:Positive
Answer:
It's actually Neutral
Explanation:
equal number of negative electric charges (the electrons) and positive electric charges (the protons).
PLEASE HELP
An engineer is designing a tire for heavy machinery, which statement
describes the clearest constraint that applies to the solution?
A. It must cost the consumer less than $200 per tire.
B. It must function safely under a heavy load.
C. It must be designed so that it has an appealing appearance.
D. It must be affordable for consumers.
Answer: it’s A
Explanation:
Answer:
It's A
Explanation:
A combustion reaction occurs between one molecule of methane (CHa) and two molecules of oxygen (O2).
How many atoms of carbon, hydrogen, and oxygen make up the products for this combustion reaction?
O A) 1 carbon, 1 hydrogen, and 1 oxygen
O B) 1 carbon, 1 hydrogen, and 2 oxygen
O C) 1 carbon, 4 hydrogen, and 2 oxygen
OD) 1 carbon, 4 hydrogen, and 4 oxygen
The total number of atoms make up the products :
D) 1 carbon, 4 hydrogen, and 4 oxygen
Further explanationComplete combustion of Hydrocarbons with Oxygen will produce CO₂ and H₂O compounds.
If O₂ is insufficient there will be incomplete combustion produced by CO and H and O
Hydrocarbon combustion reactions (especially alkanes)
For combustion of methane (CH₄) and two molecules of oxygen (O₂).
[tex]\tt CH_4+2O_2\rightarrow CO_2+2H_2O[/tex]
The number of atoms make up the products
CO₂ : 1 carbon, 2 oxygen
2H₂O : 4 hydrogen , 2 oxygen
The total number of atoms make up the products :
D) 1 carbon, 4 hydrogen, and 4 oxygen
Combustion Reaction:Combustion is a chemical process in which a substance reacts rapidly with oxygen and gives off heat.
Combustion of Hydrocarbons with Oxygen will produce CO₂ and H₂O compounds.
If O₂ is insufficient there will be incomplete combustion produced by CO and H and OFor combustion of methane (CH₄) and two molecules of oxygen (O₂).The number of atoms make up the products:CO₂ : 1 carbon, 2 oxygen
2H₂O : 4 hydrogen , 2 oxygen
Thus, the correct option is D.
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I need help with 2, 3, and 4 please help i will give the brainliest
Answer:
2=2.28*10^5
3=3.98*10^3
4=5.76*10^3
3 examples of substance that are soluble in water?
Answer:
salt, rocks, blah
Explanation:
Answer:
We call substances that dissolve in water soluble. Sugar and salt are examples of soluble substances. You'll need Transparent containers – test tubes or beakers. Water ( warm and cold ) Substances to try to dissolve eg. sugar, coffee, pepper, sand, flour, salt.Explanation:
Hope this helpsWhich of the following best describes an electron?
A. It has no charge and about the same mass as a proton.
B. It has a negative charge and much less mass than a proton.
C.It has a positive charge and much more mass than a neutron.
D.It has a negative charge and about the same mass as a neutron.
Answer:
It's D. because it has negative charge and same mass as neutrons
How can some of the difficulties caused by the Down Syndrome be over come?
In a system with 4 atoms and 1 lone pair, predict whether the lone pair will be in a B site or an A site? Explain.
Answer:
B
Explanation:
The compound corresponds to a molecule AX4E where A is the Central atom, X are the other atoms present and E is the lone pair of electrons.
The shape of this molecule is based on a trigonal bipyramid since the molecule contains five electron domains.
Since there are four bond pairs and one lone pair, the molecular geometry is see-saw with equatorial bond angle <120° and axial bond angle <90°.
For AX4E (five electron pairs), the lone pair should occupy an equatorial position instead of an axial position since the equatorial position has two neighboring electron pairs that are positioned at about 90° apart from each other and two other neighboring electron pairs that are positioned at 120° from each other. The axial position has 3 neighboring electron pairs positioned at 90° from each other and another neighboring electron pair positioned at 120°. Hence the equatorial position experiences lesser repulsion compared to the axial position.
Hence in the structure pictured in the question, position B is a preferred position for the lone pair instead of position A.
Why is creativity Important and construction scientific methods?
I
Explanation:
Sometimes it is necessary to put forth new theories to explain experimental results, Explanation:
Creativity is important to science because sometimes, it is necessary to put forth new theories to explain experimental results. Theories are explanation of scientific observations.
Answer: Without creativity, it would be difficult to come up with new methods to answer scientific questions, meaning we likely wouldn't learn anything new.
Explanation: took the quiz
How do the scientists Mendeleev and Moseley differ on their arrangement for the periodic table? A) Their periodic table was arranged the same. B) Moseley arranged the elements based on atomic masses while Mendeleev arranged the elements based on atomic number. C) Moseley arranged the elements based on atomic numbers while Mendeleev arranged the elements based on atomic masses. D) Moseley arranged the elements based on the number of protons while Mendeleev arranged the elements based on x-ray frequency.
Answer:
C is correct
Explanation:
the person above me is also correct hope this helps
The key difference between Dmitri Mendeleev and Henry Moseley's periodic table arrangements lies in the fundamental basis of their organization: C) Moseley arranged the elements based on atomic numbers while Mendeleev arranged the elements based on atomic masses.
Dmitri Mendeleev (1869): Mendeleev's periodic table was the first successful attempt at organizing the elements. He arranged the elements in order of increasing atomic masses and grouped them based on their chemical properties. Mendeleev's periodic table also left gaps for elements that were yet to be discovered, predicting their properties based on the trends of the known elements.
Henry Moseley (1913): Moseley's contribution to the periodic table was the realization that the atomic number (number of protons in the nucleus of an atom) was a more fundamental property than atomic mass. Moseley proposed that the periodic table should be arranged based on increasing atomic numbers rather than atomic masses. This arrangement resulted in a more accurate and systematic organization of the elements.
Learn more about atomic masses from the link given below.
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PLEASE HELP!!!!!
How much energy is needed to raise the temperature of 2.5 L of water from 20 C to 50 C? (anwer must be in Joules)
Answer:
8368 Joules
Explanation:
will ya'll help me, please
Answer:
Either A or D
But i think D
hope this helps =3
sorry if im wrong
What are some of the Properties of Liquids.
Answer:
Liquids take on the shape of their container. The liquid state of matter is an intermediate phase between solid and gas. Like the particles of a solid, particles in a liquid are subject to intermolecular attraction; however, liquid particles have more space between them, so they are not fixed in position.
Explanation:
A muffin has a mass of 100g and a volume of 500cm^3. What is the density of the muffin
Answer:
d = 0.2 g/cm³
General Formulas and Concepts:
Density = mass / volume
Explanation:
Step 1: Define
m = 100 g
V = 500 cm³
d = ?
Step 2: Find density
Substitute: d = 100 g/500 cm³Evaluate: d = 1/5 g/cm³Evaluate: d = 0.2 g/cm³Does the number of molecules change when a substance changes state?
Answer:
Molecules do't break up and reform when a substance boils and cools. Particles stay the same size and shape during state changes.
Explanation:
brainliest will be appreciated
The molarity of 8 grams of an aqueous solution of sodium hydroxide in 2 liters of solution is what?
Answer: 0.125
Explanation:
8g divided by 39.997. Then divide that answer by 2.
Answer:
0.1 M
Explanation:
Is this isotope stable or radioactive?
Answer:
radioactive
Explanation:
becasue i said so. Periodt
Answer:
An unstable isotope emits some kind of radiation, that is it is radioactive.
Explanation:
How did Moseley establish a more accurate periodic table?
Assume that an object has been placed in the pan of a triple beam balance. The
scales of the balance are shown below. What is the mass of the object?
Answer:
190.4 g
Explanation:
To obtain the mass of the object, we must be able to obtain the reading of the triple beam balance.
Thus, the reading of the balance can be obtained by simply adding the various values as indicated by the pointer in each scale.
This can be obtained as follow:
Scale 1 = 90 g
Scale 2 = 100 g
Scale 3 = 0.4 g
Reading of the balance = Scale 1 + Scale 2 + Scale 3
Reading of the balance = 90 + 100 + 0.4
Reading of the balance = 190.4 g
Thus, the mass of the object as indicated by the triple beam balance is 190.4 g.