How are Earth's continents related?
Please help due at 11:45!
Hair is composed of a protein called cellulose
O
True
O False
Answer:True
Explanation:
Iv done this before
What is the total number of electrons in an atom of an element with an atomic number of 18 and a mass number
of 40?
a. 58
c. 22
b. 18
d. 40
Answer:
18
Explanation:
In neutral atom protons and electrons are equal in number as it atomic number or proton number is 18 so electrons are also 18
The total number of electrons in an atom of an element with an atomic number of 18 and a mass number of 40 is 18.
What are the difference between atomic number and atomic mass ?Atomic mass can be defined as the total number of neutrons and protons located in nucleus of an element while atomic number is the number of protons present in the nucleus of element.
Atomic mass can be defined as the average weight of an element where as the atomic number is the total number of protons present in the nucleus; Atomic mass have the symbol A while atomic number have the symbol the letter Z.
Different isotopes of an element are differentiated by atomic mass is while isotopes share the same atomic number, in neutral atom protons and electrons are equal to atomic number or proton number is 18 and electrons are also 18
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A neutral atom of beryllium (Be) has an average mass of 9 amu and 4 electrons. How many neutrons does it have?
13
5
9
4
Answer:
It has 5 neutrons
Explanation:
The fact that it is a neutral atom tells us that the number of electrons and protons is the same:
The problem tells us there are 4 electrons, thus there are 4 protons.The average mass of an atom is the sum of the number of protons and the number of neutrons:
Mass = # Protons + # NeutronsWith the above information in mind we can calculate the number of neutrons:
9 amu = 4 Protons + # Neutrons# Neurons = 5 NeutronsShow your work with good use of units, rounding, and significant figures. [Hint: it is good practice to show the value of your answer before you round off to the final answer with the correct significant figures!]
(8 points) How much heat is required to convert 10.00 g of ice at –20.00°C to water at 25°C. The specific heat of ice is 2.09J/g°C; the specific heat of water is 4.182 J/g°C; the heat of fusion is 333.0 J/g.
Group of answer choices
Heat required : 4.8 kJ
Further explanationThe heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
The heat needed to raise the temperature
Q = m . c . Δt
1. heat to raise temperature from -20 °C to 0 °C
[tex]\tt Q=10\times 2.09\times (0-(-20)=418~J[/tex]
2. phase change(ice to water)
[tex]\tt Q=10\times 333=3330~J[/tex]
3. heat to raise temperature from 0 °C to 25 °C
[tex]\tt Q=10\times 4.18\times (25-0)=1045~J[/tex]
[tex]\tt Q~tot=418+3330+1045=4793~J\rightarrow rounding~and~2~sig~figs=4.8~kJ[/tex]
1. What is the atomic mass of hydrogen if 99.985% is hydrogen-1 and 0.015% is hydrogen-2?
The atomic mass of Hydrogen : 1.02985
Further explanationIsotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.
Mass atom X = mass isotope 1 . % + mass isotope 2.% ..
99.985% is hydrogen-1 and 0.015% is hydrogen-2
The atomic mass of Hydrogen :
[tex]\tt atomic~mass~H=0.99985\times 1+0.015\times 2\\\\atomic~mass~H=1.02985[/tex]
is bird seed homogeneous or heterogeneous
Answer:
heterogeneous
In order to give birds a varied and balanced diet, commercial bird seed blends typically include a range of seeds, grains, and other substances. As a result, bird seed is frequently categorised as a heterogeneous blend.
A seed is referred to as homogenous if its genetic makeup, size, shape, and other traits are all consistent. To guarantee consistency in the ensuing plants, these seeds are typically created through controlled breeding or genetic manipulation. A heterogeneous seed, on the other hand, is one that varies in genetic makeup, size, shape, and attributes. These seeds frequently result from cross-pollination or natural pollination between various species or kinds.
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All of the alkaline earth metals are similar in that – they are all artificially made elements they all have similar atomic weights. they all have the same ionic charge. they all show variable valences.
Answer:
they all have the same ionic charge.
Explanation:
Alkaline earth metals are group 2 metals on the periodic table. They are divalent elements because they have two valence electrons and ionize by donating these two valence electrons. Elements in this group have the same numbers of electrons in their outermost shell of their atoms. i.e. they all have the same number of valence electrons and ionic charge.
I will give you Brainly if you awser correct if your gonna awser for points pl put I don’t know
Answer:
C
Explanation:
what is the density of a liquid if it's volume is 125 mL and it's mass is 50g?
Answer:
0.4g/ml
Explanation:
density= mass/volume
density=50g/125ml
density=0.4g/ml
if u know that answer i will mark has brainliest
Answer:
The clear liquid is less dense than the black liquid, which is why it floats on top. If the volume were different, you would visually see more clear liquid than black and vice versa.
The clear liquid is less dense than the black liquid
Answer:
A. The clear liquid is less dense than the black liquid
Explanation:
Since the clear liquid since on top of the black one it's density is less. Whatever liquid has a higher density will sink to the bottom of the flask.
A reversible reaction is said to be in equilibrium when
A)
all reactions stop leaving some reactant unused.
B)
the reaction goes to completion and no reactants are left.
9)
the rate of the backward reaction equals the rate of the forward reaction.
D)
the reaction rate of the backward reaction becomes larger than the rate of
the forward reaction.
Answer: C) the rate backward reaction equals the rate of the forward reaction.
Explanation:
The
the surface area of the reactants, the faster the reaction rate.
A. greater
B. lesser
FOR 50 POINTS & A BRAINIST*
1.) For an atom of sulfur, there are
A.) two electron shells with 6 valence electrons
B.) three electron shells with 6 valence electrons
C.) four electron shells with 6 valence electrons
D.) five electron shells with 6 valence electrons
2.) Which atom has four electron shells with 7 valence electrons?
A.) F
B.) CI
C.) Br
D.) I
3.) Which atom has three electron shells with 8 electrons in its outermost orbit?
A.) He
B.) Ne
C.) Ar
D.) Kr
4.) Which method should be used to draw electrons that are involved in a collision during a chemical reaction?
A.) Bohr's model
B.) Lewis dot model
C.) Addition model
D.) Subtraction model
Answer:
1. B
2. C
3. C
4. B
Explanation:
1. An atom of sulfur has an atomic number of 16. It has three electron shells and six valence electrons, therefore, it belongs to period 3, group VIA of the periodic table
2. Bromine has an atomic number of 35. It belongs to period 4 group VIIA of the periodic table. Therefore, it has four electron shells and seven valence electrons.
3. Argon has an atomic number of 18. It belongs to period 3, group IVA of the periodic table. Therefore, it has three electron shells and eight valence electrons.
4. The Lewis dot model use structures that represent the valence electrons of atoms within a molecule existing as lone pairs or when involved in bonding. They can be used to draw electrons that are involved in a collision during a chemical reaction.
THIRTY POINTS I NEED HELP HURRY What is the volume of the cone?
Answer:
V=πr2h 3
Explanation: I would give more but need more i information
Answer:there u go
Explanation:The volume V of a cone with radius r is one-third the area of the base B times the height h . Note : The formula for the volume of an oblique cone is the same as that of a right one. ... If the heights of a cone and a cylinder are equal, then the volume of the cylinder is three times as much as the volume of a cone
Which best explains the difference between a monomer and a polymer?
A monomer is larger than a polymer.
A monomer contains carbon and a polymer does not.
A polymer contains carbon and a monomer does not.
A polymer is larger than a monomer.
The difference between the monomer and a polymer should be that monomer should be larger than a polymer.
Difference of monomer and a polymer?The monomer represent the molecule type where it has the capability for chemically the bond along with the other molecules with respect to the long chain. While the polymer should represent the chain of the non-specified the no of monomers.
Also, it represent the building blocks of polymers that contain more complex type of molecules
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Answer:
A
Explanation:
two or more atoms joined together form a _______
Answer:
When two atoms join together they make compounds
Explanation:
A molecule is formed when two or more atoms join together chemically. If atoms combine that are of two or more different elements, we call that a compound. All compounds are molecules, but not all molecules are compounds.
By examining the diagram, which of the following is NOT needed for photosynthesis:
O sunlight
O carbon dioxide
O water
oxygen
another science question plz answer ASAP b/c its timed
Answer:
D
Explanation:
How do HOT AIR BALLOONS work when ascending and descending explain in terms of gas behavior?
Answer: Animation: Burning gas makes the air inside the balloon less dense, producing an upward force or lift. 1) A hot air balloon stays on the ground (or descends) when the air inside it is too cool. ... 3) When the air is hotter still, the balloon rises because the lift force is greater than the weight.
Explanation:
Common sense
are Li, Na and K in the same group
Answer: Yes, they are.
Explanation:
Yes, they are. Li, Na, and K are referring to Lithium, sodium, and potassium.
They are all belonging to the same group which is called the alkali metals group.
They are having the same number of valence electrons i.e. 1.
This group of the alkali metals are considering tree more metals in it which are Rb, Cs, and Fr.
an atom has 11 protons, 12 neutrons, and 11 electrons. what is the charge of the atoms nucleus?
A) +11
B) -11
C) 0
D) 23
Answer:
Since sodium has 11 protons, the number of neutrons must be 23 – 11 = 12 neutrons.
Explanation:
A beaker containing 6.32 moles of PBr3, contains___
molecules of PBrz.
A) 1712.7
B) 3.1 x 10^24
C) 3.8 x 10^24
D) 271
Answer:
3.8 x 10²⁴molecules
Explanation:
Given parameters:
Number of moles = 6.32moles
Unknown:
Number of molecules = ?
Solution:
The number of moles can be used to derive the number of molecules found within a substance.
Now,
1 mole of substance contains 6.02 x 10²³ molecules
6.32 mole of PBr₃ will contain 6.32 x 6.02 x 10²³ = 3.8 x 10²⁴molecules
Explain why the electron configuration of 2-3-1 represents an atom in an excited state?
Answer:
See explanation
Explanation:
If we look at the electron configuration closely, we will discover that the element must have had a ground state electron configuration of 2,4.
This is because, the innermost shell usually holds two electrons while the outer shells hold eight electrons each. The four electrons must be accommodated in the second shell in the ground state configuration of the compound.
However, when the atom is excited, one electron from this shell may move to the third shell to give the excited state configuration 2-3-1 as shown in the question.
You are sitting in the central park bleachers of a Major League baseball park. You see a batter strike a pitched ball. About 0.4 seconds later you hear the contact between the bat and the ball. In terms of the properties of light and sound waves, how do you explain the difference in the communications you receivedbabout the same event?
Answer:
See the answer below
Explanation:
The speed of light in air and space is faster than the speed of sound in the same media. Light travels with a speed of approximately 3 x [tex]10^8[/tex] m/s while sound can only travel at 343 m/s (at 20 [tex]^oC[/tex]).
Consequently, the visuals of a batter striking a pitched ball which travel by light and is perceived through the eyes would be seen before the sound of the strike.
The difference in the speeds of light and that of sound largely explains the difference in the communication received about seeing a batter striking a pitched ball before hearing the sound of the strike
atoms are so small that approximately _______ of them can fit at the end of a needle?
Answer:
5 million million atoms can fit at the end of a needle
Answer:
Let's just say 5 million million hydrogen atoms could fit at the end of a needle.
Explanation:
Atoms are 100 picometers, and to compare, the amount of even 1 centimeter, a calculator can't even figure out how many picometers are in a centimeter because there is just too much picometers.
true or false, vaporization that occurs at the surface of a liquid is called evaporation
Answer:
True
Explanation:
Vaporization that happens below the surface is boiling, above the surface is evaporation :)
Answer:
True
Explanation:
it evaporates because of the temperature difference
Which of the following has the larger atomic radius?
O Cs
O Ca
O Li
O Ba
Hope it helps
Which sentence best explains the relationship between pressure and the
solubility of a gas?
A. The greater the pressure, the more gas that will dissolve.
B. Solubility increases with pressure for some gases but not others.
C. The lower the pressure, the more gas that will dissolve.
D. Pressure has no effect on the solubility of gases.
Answer: A. The greater the pressure, the more of gas that will dissolve.
Explanation: Increasing pressure increases the solubility of gases. It has little effect on the solubility of liquids and solids.
Think about how particles are arranged inside atoms. Please name and describe those three particles, and describe how the particles are arranged inside atoms. Some topics to include are: the charge of the particles, the mass of the particles, and where the particles are located.