Answer:
true
Explanation:
photons are emitted when electrons move from from a lower energy level to a higher energy level
A molecule that has a linear shape has two electron domains around the central atom. How
many lone pairs of electrons are present around the central atom?
A. zero
B. one
C. two
D. three
Answer:
C I think.
Explanation:
Sorry if it's wrong :(
HELP PLEASE
Describe and illustrate how liquids are different then the other states of matter.
Explanation:
There are four natural states of matter: Solids, liquids, gases and plasma. ... Solids also have a high density, meaning that the particles are tightly packed together. Liquids. In a liquid, the particles are more loosely packed than in a solid and are able to flow around each other, giving the liquid an indefinite shape.
What is matter?
A.
Anything that has energy
B.
Anything that changes volume
C.
Anything that takes up space
D.
Anything that produces heat
a b c or d no bull
Answer:
C. Anything That Takes Up Space.
Explanation:
The process by which vesicles move substances out of a cell is
The water cycle would not be possible without ______ and ________.
a. evaporation; condensation
b. gravity; sun
c. precipitation; rain
d. gravity; precipitation
the density of a wooden block that has a volume of 5 cm3 & a mass of 30.5 g
Formula: ____________
Mass = ____
Volume = ____
Density = ____
Answer:
The answer is 6.10 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 30.5 g
volume = 5 cm³
We have
[tex]density = \frac{30.5}{5} \\ [/tex]
We have the final answer as
6.10 g/cm³Hope this helps you
what is the formula for zinc sulfide
Answer:
the formula for zinc sulfide is b. ZnS
A sample of ammonia gas has a volume of 3213 mL at 11°C and a pressure of 822 torr. What will the volume of the gas be in liters if the
moles of gas and the temperature do not change but the pressure changes to 2.33 atm?
Answer:
We are given:
v1 = 3.2 L v2 = x L
p1 = 822 torr OR 1.08 atm p2 = 2.33 atm
t1 = t2 = 284 k
From the Ideal gas equation:
PV = nRT
Since the number of moles (n), universal gas constant (R) and Temperature (T) are constant
PV = k (where k is a constant)
it can also be written as:
P1V1 = k --------------------------(1)
Similarly,
P2V2 = k (where k is the same constant as before)----------(2)
Solving for V2:
From (1) and (2):
P1V1 = P2V2
Replacing the variables
1.08 * 3.2 = 2.33 * x
x = (1.08 * 3.2)/2.33
x = 1.5 L (approx)
Therefore, the final volume of the solution will be 1.5L
Which element in period 5 has the largest atomic radil
Answer:
francium is the answer
Explanation:
It should be noted that the element in period 5 has the largest atomic radius is Francium.
What is an atomic radius?It should be noted that an atomic radius simply means the measure of the size of the atom from the center of the nucleus.
In this case, the element in period 5 has the largest atomic radius is Francium while Helium has the smallest radius.
Learn more about atomic radius on:
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Which changes MUST happen for elements to become a compound
Answer:
Chemical changes in compounds happen when chemical bonds are created or destroyed. Then the molecular structure changes; new molecules form and a new substance is created. Often heat is used to begin a chemical change, as when baking a cake. Another example of a chemical reaction is the rusting of a metal trash can.
Hope this helps you Do mark as brainliest ✌️An element is constituted of only atoms and no other entities are present in it. Whereas a chemical compound is a substance made up of various identical molecules of the same or different atoms.
The atoms of the same or different species bond together to form a compound.
Chemical bonding is present among them that cannot be simply separated.The compounds can have ionic, covalent and hydrogen bonds present in them.When the new atoms combine the structure changes of the new molecule formed.To learn more about compounds and atoms follow the link:
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In two to three sentences, explain the trend for atomic size. Why does this trend occur?
Answer:
The number of energy levels increases as you move down a group as the number of electrons increases. Each subsequent energy level is further from the nucleus than the last. Therefore, the atomic radius increases as the group and energy levels increase. 2) As you move across a period, atomic radius decreases.
Explanation:
What is the function of the esophagus?
The esophagus functions primarily as a transport tube that directs the progression of food and fluids from the mouth to the stomach.
WILL MARK BRAINLIEST (if correct)
C or D i think maybe
Answer:
D and A
Explanation:
What ingredients can be alternative for cornstarch?
Answer:
their are many alternative for cornstarch.But I know only 10 of them and they are:
1.Rice Flour
2.wheat Flour
3.Potato Starch
4.Arrowroot
5.Tapioca
6.Ground Flaxseeds
7.Gaur Gum
8.Xanthan Gum
9.Glucomannan
10.Xanthan Gum
Lily feels tired and weak in the evenings after work. Before starting her chores, she eats dinnner. Which characteristic of life does Lily Exhibit?
Answer:
cool
Explanation:
please help me i don’t know the answer to this!!!!!!
Answer: Lithium and Ethanol
Explanation: As lithium and ethanol both have a density of under
1.000g/ml, they can be supported by the water. Blood and Magnesium are denser than the water and will therefore sink as the water can not support it them.
50 POINTS
Assume that the variables x and y are inversely related. If k = 18, what is the value of y for each of the following points?
Be sure and record your data to be used in the following problem.
х y k
1 18
A: 18,0.05,9
2 18
A: 0.11,36,9
3 18
A: 0.16,6,54
6 18
A: 0.33,108,3
9 18
A: 162,0.5,2
18 18
A: 324,0.75,1
Answer:
9/.05=180. I think it's 1
Explanation:
If x and y are inversely proportional then the product of xy =k or y=k/x
The specific heat of silver is 0.24 J/g•°C. How many joules of energy are needed to warm 4.37 g of silver from 25.0°C to 27.5°C?
A. 2.6 J
B. 46 J
C. 0.14 J
D. 0.022 J
The heat energy needed to change the temperature of 4.37 gram of silver sample of specific heat 0.24 J/ g °C from a temperature of 25 to 27.5 °C is 2.6 J.
What is calorimetry ?Calorimetry is an analytical technique used to determine the heat energy absorbed or released by a system. The calorimetric equation relating the heat energy q with the mass of the substance m, specific heat c and temperature difference ΔT is given as:
q = m c ΔT.
Given that the mass of the sample of iron = 20 g
temperature difference ΔT = 27.5 - 25 = 2.5 °C
specific heat c = 0.24J/ g °C.
The heat energy absorbed by the sample is calculated as follows:
q = 4.37 g × 0.24 J/ g °C × 2.5 °C
= 2.6 J.
Therefore, the heat energy required to the raise the temperature of the sample of iron is 2.6 J.
Find more on calorimetry :
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Releases sugar (glucose) into the blood stream to power cells A. Brain B. Heart C. Liver D. Stomach and intestines
Answer:
C Liver
Explanation:
Which of the following molecules has a trigonal pyramidal shape?
CO
Ni ---CO
A.
СО
OBCI-S c
Xeo
O.
O C.
0-N
Answer:
Xeo
Explanation:
A is the molecules with the trigonal pyramid shape
A chef fills a 60 mL container with 52.2 g of cooking oil. What is the density of the oil?
Answer:
The answer is 0.87 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{52.2}{60} \\ [/tex]
We have the final answer as
0.87 g/mLHope this helps you
D 14 3
N
7
What is the number of protons, neutrons, and electrons?
Answer:
14
Explanation:
For example, silicon has 14 protons and 14 neutrons. Its atomic number is 14 and its atomic mass is 28. The most common isotope of uranium has 92 protons and 146 neutrons. Its atomic number is 92 and its atomic mass is 238 (92 + 146).
Non Polar covalent bonds are between
Answer:
atoms that share a pair of electrons with each other
Explanation:
Lead(II) nitrate and ammonium iodide react to form lead(II) iodide and ammonium nitrate according to the reaction
Answer:
1.186L or 1186mL.
Explanation:
The volume of a 0.290 m NH4I solution that is required to react with 253 ml of a 0.680 m Pb(NO3)2 solution is 1.186 liters or 1186 ml.
List the factors that cause low oxygen levels.
Answer:
Common causes of hypoxemia include:
Anemia.
ARDS (Acute respiratory distress syndrome)
Asthma.
Congenital heart defects in children.
Congenital heart disease in adults.
COPD (chronic obstructive pulmonary disease) exacerbation — worsening of symptoms.
Emphysema.
Interstitial lung disease
and many more.....
297.85
Question 2
4 pts
If a sample of gas occupies 23.5 mL at 315 K and 14.8 atm of pressure, what volume will it occupy at 415 K and
12.3 atm?
Give your volume in ml, but do not include the units in the answer. Do not use scientific notation.
Question 3
4 pts
Answer:
37.25
Explanation:
[tex]P_1[/tex] = Initial pressure = [tex]14.8\ \text{atm}[/tex]
[tex]P_2[/tex] = Final pressure = [tex]12.3\ \text{atm}[/tex]
[tex]V_1[/tex] = Initial volume = [tex]23.5\ \text{mL}[/tex]
[tex]V_2[/tex] = Final volume
[tex]T_1[/tex] = Initial temperature = [tex]315\ \text{K}[/tex]
[tex]T_2[/tex] = Final temperature = [tex]415\ \text{K}[/tex]
From ideal gas law we have
[tex]PV=nRT[/tex]
[tex]\Rightarrow PV\propto \dfrac{1}{T}[/tex]
So
[tex]\dfrac{P_1V_1}{T_1}=\dfrac{P_2V_2}{T_2}\\\Rightarrow V_2=\dfrac{P_1V_1T_2}{T_1P_2}\\\Rightarrow V_2=\dfrac{14.8\times 23.5\times 415}{315\times 12.3}\\\Rightarrow V_2=37.25\ \text{mL}[/tex]
The final volume is [tex]37.25\ \text{mL}[/tex]
Isotopes have
Question 1 options:
A)
different numbers of both protons and neutrons in their nuclei.
B)
a different number of neutrons in their nuclei.
C)
a different number of protons in their nuclei.
D)
a different number of electrons.
Question 2 (5 points)
An aqueous solution
Question 2 options:
A)
must contain three or more substances.
B)
is a single-phase heterogeneous mixture.
C)
has water as the solvent.
D)
has water as the solute.
Question 3 (5 points)
Which of the following is a homonuclear diatomic molecule?
Question 3 options:
A)
NH3
B)
CO
C)
2CO2
D)
H2
Question 4 (5 points)
Given a container of a solution of 5% HCl, all samples tested from this same bottle will have the same mass ratio of hydrogen to chlorine. This is an application of
Question 4 options:
A)
the law of conservation of energy.
B)
the law of multiple proportions.
C)
the law of conservation of mass.
D)
the law of constant composition.
Question 5 (5 points)
Elements in the same period
Question 5 options:
A)
have the same principal quantum number.
B)
form bonds with the same type of elements.
C)
have the same number of valence electrons.
D)
have the same number of protons.
Question 6 (5 points)
Which of the following contribute(s) to most of the mass of an atom?
Question 6 options:
A)
Neutrons only
B)
Protons and neutrons
C)
Protons and electrons
D)
Protons only
Question 7 (5 points)
In a certain chemical reaction, the bonds of the products contain more energy than the bonds of the reactants. For the reaction to occur, which of the following best describes what occurred?
Question 7 options:
A)
Energy was released, so the reaction is endothermic.
B)
Energy was released, so the reaction is exothermic.
C)
Energy was added, so the reaction is endothermic.
D)
Energy was added, so the reaction is exothermic
Question 8 (5 points)
A solution
Question 8 options:
A)
is a single-phase homogeneous mixture.
B)
must contain water.
C)
is always a liquid.
D)
can contain more than two phases.
Question 9 (5 points)
Which of the following is true of alloys?
Question 9 options:
A)
They can only be composed of metals.
B)
They must be held together by chemical bonds.
C)
They're liquid solutions.
D)
They must contain a metal.
Question 10 (5 points)
Which of the following best describes an atomic number? An element's identity is defined by its atomic number; this means it represents the number of
Question 10 options:
A)
electrons in the element.
B)
neutrons in its nucleus.
C)
protons plus neutrons in its nucleus.
D)
protons in its nucleus.
Question 11 (5 points)
Electrons in the outermost shell of an atom that are available to bond with the electrons of other atoms are
Question 11 options:
A)
cations.
B)
free electrons.
C)
valence electrons.
D)
anions.
Question 12 (5 points)
Main group elements have valence electrons in which suborbitals?
Question 12 options:
A)
d and f
B)
s and p
C)
p and f
D)
s and d
Question 13 (5 points)
Molecules have
Question 13 options:
A)
only kinetic energy.
B)
only potential energy.
C)
both potential and kinetic energy.
D)
neither kinetic nor potential energy.
Question 14 (5 points)
The majority of elements are
Question 14 options:
A)
metalloids.
B)
nonmetals.
C)
metals.
D)
inert.
Question 15 (5 points)
A student found the mass of an object to be 26.5 g. To find the volume, the student submerged the object in a graduated cylinder of water. Submerging the object in the water in the graduated cylinder increased the water level by 24.1 mL. The density of the object is
Question 15 options:
A)
1.0906 g/mL.
B)
0.909 g/mL.
C)
1.10 g/mL.
D)
1.1 g/mL.
Question 16 (5 points)
Mass and energy are conserved
Question 16 options:
A)
only in chemical changes.
B)
in chemical changes and physical changes.
C)
always in physical changes and sometimes in chemical changes.
D)
only in physical changes.
Question 17 (5 points)
Which of the following can't be broken down any further chemically?
Question 17 options:
A)
Compounds
B)
Elements
C)
Matter
D)
Molecules
Question 18 (5 points)
A/an _______ is the smallest unit of matter that has the characteristics of a chemical element.
Question 18 options:
A)
atom
B)
proton
C)
molecule
D)
electron
Question 19 (5 points)
The distance between consecutive peaks or troughs in a wave is
Question 19 options:
A)
frequency.
B)
displacement.
C)
amplitude.
D)
wavelength.
Question 20 (5 points)
The phase transition of dry ice (frozen carbon dioxide) to gas is an example of
Question 20 options:
A)
condensation.
B)
sublimation.
C)
deposition.
D)
vaporization.
I WILL GIVE BRAINLIEST IF YOU CAN ANSWER THEM
Answer:
b
Explanation:
dueto isotopes haveno thesame neutral numbee hence b iscorrect
Answer:
b
Explanation:
A cough syrup contains red dye #40, with a concentration of 4.68 x 10-3 M.a.If you dilute the cough syrup by adding 175 mL of water to a 250. mL sample of the cough syrup, what will be the final concentration?
How do I do this?
Answer:
[tex]M_2=2.75x10^{-3}M[/tex]
Explanation:
Hello.
In this case, since a dilution process is a process by which the concentration of a solution decreases due to the increase of volume by usually adding water, it is important to take into account that the moles remain unchanged:
[tex]n_1=n_2[/tex]
Whereas in terms of molarity (M=n/V) can be written as:
[tex]M_1V_1=M_2V_2[/tex]
In such a way, since the initial concentration is 4.68e-3 M and the volume of such solution is 250. mL, the final volume results from mixing 250 mL of this solution with 175 mL, that is, to a volume of 425 mL. Thus, the concentration turns out:
[tex]M_2=\frac{M_1V_1}{V_2} =\frac{4.68x10^{-3}M*250.mL}{425.mL} \\\\M_2=2.75x10^{-3}M[/tex]
Best regards.
If you dilute the cough syrup by adding 175 mL of water to a 250 mL sample of the cough syrup, the final concentration would be 0.00275 M
Using a simple dilution equation:
number of moles before dilution = number of moles after dilution
Recall that: number of moles = molarity x volume (MV)
Thus:
M1V1 = M2V2
In this case, M1 = 4.68 x 10-3 M, M2 = ? V1 = 250 mL, and V2 = 425 mL
M2 = 4.68 x 10^-3 x 250/425
= 0.00275 M
= 0.00275 M
More on dilution principle can be found here: https://brainly.com/question/13844449
How many total hydrogen atoms are in CH3OOH?
Answer:
4
Explanation:
In CH3OOH, there is H3, which means 3 hydrogen atoms, but there is also an H at the end, which means another hydrogen atom.
3 + 1 = 4
How would you expect a positive particle approaching another positive particle to behave?
Answer:
They would produce a repulsive force to another
Explanation:
A positive particle approaching another positive particle will repulse it.
According to coulomb's law "like charges repel one another and unlike charges attract".
A charge is an intrinsic property of any matter.
When like charges e.g positive and positive or negative and negative charges are in the vicinity of one another, they repel each other.
When unlike charges; positive and negative are brought together, they simply attract one another.
Therefore, we expect that a positive particle approaching another positive particle will repel one another.
When a positive particle approaches another positive particle, the two particles repel or move away from each other.
In electrostatics we know that like charges repel while unlike charges attract. Therefore when we have two like charges, they simply move away from each other. This is known as repulsion of charges.
Hence, two positive charges approaching each other will simply move away and repel each other according to the laws of electrostatics.
Learn more: https://brainly.com/question/1340584