Answer:
Rubidium 265 pm
Explanation:
As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period
Hydrogen 53 pm
Lithium 167 pm
Sodium 190 pm
if the freezing point of a substance is 68°C, what is its melting point?
The melting point of the substance has been [tex]\rm 68^\circ C[/tex].
The freezing point has been defined as the temperature above to which the substance exists in the liquid state, while below which the substance exist in the solid state.
Freezing point and melting pointThe melting point has been the temperature at which the solid starts to convert into the liquid state. The melting point and freezing point for the substances has been the same temperature.
Thus, the melting point of the substance whose freezing point has been [tex]\rm 68^\circ C[/tex] has been [tex]\rm 68^\circ C[/tex].
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Classify the following as an element, compound, homogeneous mixture, or heterogeneous
mixture: salt water
A. Element
B. Compound
C. Homogeneous mixture
D. Heterogenous mixture
If 11 moles of A are combined with 16 moles of B and the reaction occurs to the greatest extent possible, how many moles of C form?
Pressure increases from Earth’s surface toward the center of Earth.
True Or False
Answer:
True
Explanation:
The center receives pressure which is what creates convection currents
The topmost layer of the Earth is made up of large pieces that fit together like a puzzle. However, these pieces don't stay still, and sometimes they rub against each other. When these large sections of the Earth’s crust, called tectonic plates, hit each other, they send vibrations through the surface of the Earth. These vibrations are seismic waves. Seismic waves are just like the ripples in a pond. But instead of traveling through water, they travel through the Earth. When they reach the Earth's surface, they make the ground shake. That's an earthquake.
Earthquakes are the result of?
A ripples traveling through water.
B Earth’s topmost layer sinking.
C vibrations from seismic waves.
D tectonic plates staying still.
Answer:
C- vibrations from seismic waves
Answer:
C vibrations from seismic waves.
Explanation:
The shifting rock in an earthquake causes vibrations called seismic waves.
What is pressure?
O A. The heat required to change the temperature of a gas
OB. The force of gas molecules hitting their container
O C. The mixing of gas molecules due to random motion
D. The space occupied by gas molecules moving around
Answer:
B.
Explanation:
The force of gas molecules hitting their container is pressure.
Because pressure = force/area.
Nonrenewable resources are ?
Answer:
limited resources
Explanation:
nonrenewable resources are those resources found inside the earth that are in a fixed amount. They are being used at a faster rate, and cannot be renewed. These resources include fossil fuels,natural gas, and coal.
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these are easily extracted with a pH solution of greater than 7? which one
A) acid drugs
B) metabolites
C) base drugs
D) derivatives
Answer:
base drugs
Explanation:
The pH scale is a scale graduated from 0-14. It is used as an indicator of the degree of acidity or alkalinity. A pH of 0-6.9 indicates acidity. A pH of 7 indicates that the solution is neutral. A solution of pH above 7 indicates that the substance is basic.
It is thus a correct statement to say that any substance that dissolves in solution to produce a solution of pH greater than 7.0 is a basic substance.
If we look at the options closely, it is only a basic drug that will dissolve in water to yield a basic solution of pH greater than 7.0 hence the answer.
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What causes blood pressure?
A.the strength of the muscles in the walls of the capillaries
B.the speed at which oxygen is returned to blood in the lungs
C. the force with which the ventricles contract
D. the rate at which blood flows through the heart
Answer:
C
Explanation:
What causes blood pressure?
C
To pump blood around the body, the heart contracts and then relaxes through the cardiac cycle. The cycle begins with the contraction of the two atria, which push blood into the ventricles. Then, the ventricles contract, which forces the blood out of the heart.
When the heart pushes blood around the body during systole, the pressure placed on the vessels increases. This is called systolic pressure.
When the heart relaxes between beats and refills with blood, the blood pressure drops. This is called diastolic pressure.
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In going through the three physical states of matter, water would normally undergo changes in
A) composition.
B) density.
C) mass.
D) weight.
Answer:
COMPOSITION
Explanation:
Brainliest plz
do rainforests have hot summers and cold winters?
Answer:
No, rainforests have long wet winters and short dry summers.
hi:) how to do 2(bi)?
Answer:
4 protons, 5 neutrons, 2 electrons
Explanation:
If you look at the numbers beside Be²⁺, the number 9 is the relative atomic mass and the number 4 is the proton (atomic) number. The relative atomic mass is the sum of the number of protons and the number of neutrons.
Number of protons= proton number.
Hence, number of protons= 4
Number of protons + neutrons= 9
4 + number of neutrons= 9
number of neutrons
= 9 -4
= 5
In an atom, the number of protons and electrons are the same since atoms are electrically neutral. But in an ion, the number of electrons is not equal to the number of protons since the atom gains/ loses electrons to form an ion. A positive sign means that electrons are given away.
Thus, Be gives away 2 electrons to form Be²⁺.
Original number of electrons= 4
Number of electrons in Be²⁺
= 4 -2
= 2
In summary, the number of protons and neutrons in an ion is the same as that of the atom. However, the number of electrons is not the same.
Answer:
Answer:
4 protons, 5 neutrons, 2 electrons
Explanation:
If you look at the numbers beside Be²⁺, the number 9 is the relative atomic mass and the number 4 is the proton (atomic) number. The relative atomic mass is the sum of the number of protons and the number of neutrons.
Number of protons= proton number.
Hence, number of protons= 4
Number of protons + neutrons= 9
4 + number of neutrons= 9
number of neutrons
= 9 -4
= 5
In an atom, the number of protons and electrons are the same since atoms are electrically neutral. But in an ion, the number of electrons is not equal to the number of protons since the atom gains/ loses electrons to form an ion. A positive sign means that electrons are given away.
Thus, Be gives away 2 electrons to form Be²⁺.
Original number of electrons= 4
Number of electrons in Be²⁺
= 4 -2
= 2
In summary, the number of protons and neutrons in an ion is the same as that of the atom. However, the number of electrons is not the same.
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The volume of a gas is 450 mL when its pressure is 1.00 atm. If the temperature of the gas does not change, what is the
pressure when its volume is changed to 2.00 L?
Use PV = P2V2.
0.225 atm
O 0.444 atm
O 2.25 atm
O 4.44 atm
Answer: 0.225 atm
Explanation:
For this problem, we have to use Boyle's Law.
Boyle's Law: P₁V₁=P₂V₂
Since we are asked to find P₂, let's manipulate the equation.
P₂=(P₁V₁)/V₂
[tex]P_{2} =\frac{(1.00atm)(0.45L)}{2.00L}[/tex]
With this equation, the liters cancel out and we will be left with atm.
P₂=0.225 atm
I’ve gotten the answer as x=.478 but when plugging back in, .46/.478 ≠ .22. Help please
Answer:
15. 2.66 moles .
16. 2.09L.
Explanation:
Molarity of a solution is simply defined as the mole of solute per unit litre of the solvent. Mathematically, it is represented as:
Molarity = mole /Volume.
With the above formula, let us answer the questions given above
15. Data obtained from the question include the following:
Volume of solution = 1.4L
Molarity = 1.9M
Mole of solute =.?
Molarity = mole /Volume
1.9 = mole / 1.4
Cross multiply
Mole = 1.9 x 1.4
Mole = 2.66 moles
Therefore, the mole of the solute present in the solution is 2.66 moles.
16. Data obtained from the question include the following:
Mole of solute = 0.46 mole
Molarity = 0.22M
Volume of solvent (water) =.?
Molarity = mole /Volume
0.22 = 0.46/Volume
Cross multiply
0.22 x Volume = 0.46
Divide both side 0.22
Volume = 0.46/0.22
Volume = 2.09L
Therefore, 2.09L of water is required.
Carbon-14 is a common isotope of the element. How many electrons
does it contain?
O 14
O 12
O 8
O 6
Count then plot the total number of atoms in the reactants to total atoms
in the products for the equation 2H2 + O2 + 2H2O
How many grams of aluminum oxide would be produced from the reaction of 0.25 grams of aluminum with excess oxygen gas?
Answer:
0.472 grams of aluminum oxide would be produced from the reaction of 0.25 grams of aluminum with excess oxygen gas.
Explanation:
First of all, you should know that the balanced reaction that occurs:
4 Al + 3 O₂ → 2 Al₂O₃
Then, by stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts are produced in moles:
Al: 4 molesO₂: 3 molesAl₂O₃: 2 molesBeing:
Al: 27 g/moleO: 16 g/moleThe molar mass of the compounds participating in the reaction is:
Al: 27 g/moleO₂: 2*16 g/mole= 32 g/moleAl₂O₃: 2*27 g/mole + 3*16 g/mole= 102 g/moleThen, by stoichiometry of the reaction, the following amounts of mass react and are produced:
Al: 4 moles*27 g/mole= 108 gO₂: 3 moles*32 g/mole= 96 gAl₂O₃: 2 moles*102 g/mole= 204 g
Now it is possible to apply the following rule of three: if 108 grams of Al produce 204 grams of Al₂O₃, 0.25 grams of aluminum how much mass of Al₂O₃ will it produce?
[tex]mass of Al_{2} O_{3} =\frac{0.25 grams of Al*204 grams of Al_{2} O_{3} }{108 grams of Al}[/tex]
mass of Al₂O₃=0.472 grams
0.472 grams of aluminum oxide would be produced from the reaction of 0.25 grams of aluminum with excess oxygen gas.
Answer:
D
Explanation:
Which of the following is an example of a mixture?
A. NaCl
B. CO2 + H2 + O2
Ос. Са
D. C6H1206
Reset Selection
Answer:
B.
Explanation:
CO2 + H2 + O2 - are 3 individual substances.
PLEASE HELP WILL GIVE 100 points
Record the data from each trial in the data chart below. Be sure to fill in the chart completely.
Test One
Parent 1: FF
Parent 2: FF
Phenotype ratio:
short fur: long fur
Test Two
Parent 1: Ff
Parent 2: FF
Phenotype ratio:
short fur: long fur
Test Three
Parent l: ff
Parent 2: ff
Phenotype ratio:
short fur: long fur
Answer: Test One
Parent 1: FF
Parent 2: FF
Phenotype ratio:
short fur: long fur
Test Two
Parent 1: Ff
Parent 2: FF
Phenotype ratio:
short fur: long fur
Test Three
Parent l: ff
Parent 2: ff
Phenotype ratio:
short fur: long fur
Explanation:
What is one way in which chemistry affects your everyday life?
A. Refrigerators use energy more efficiently than they did 10 years
ago.
B. Tap water is safe to drink because it is monitored for harmful
substances.
c. Weather forecasts are now more accurate because of radar.
D. Watches are now more accurate because they are digitalized.
Answer: B
Explanation: Water is filtered with a bunch of chemicals which makes it drinkable.
Which type of crystal is typified by a sea of delocalized electrons
surrounding the lattice?
O A. lonic
B. Metallic
OC. Macromolecular
D. Chemical
Reset Selection
B.metallic is the answer hope this helped
The correct answer is option B. Metallic.
What explains the structure of metals and delocalized electrons?
Metal is composed of a huge structure of atoms arranged in a regular pattern. Electrons from the outer shell of a metal atom are delocalized and can move freely throughout the structure. This sharing of delocalized electrons results in strong metal bonds.
Metallic bonds are electrostatic attraction between metal cations and the negatively charged ocean of delocalized electrons. The sea of delocalized electrons contains only valence electrons, not core electrons.
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CAN I PLEASE GET SOME HELP PLEASE PLEASE HELP ME I WOULD APPRECIATE IT AND THANK YOU!! WICH of the following is an expression of Avogadro's law (k=constant) A)V=kn B)V=k/n C)nV=k D)V=k no
Answer:
Vn = k
Explanation:
[tex]Vn = k[/tex]
From the web :
Avogadro's Law is stated mathematically as follows: Vn=k, where V is the volume of the gas, n is the number of moles of the gas, and k is a proportionality constant
Avogadro's Law is stated mathematically as follows: Vn=k, where V is the volume of the gas, n is the number of moles of the gas, and k is a proportionality constant.
What is Avagrado's law?
According to Avogadro's Law, all gases have an identical number of molecules in an equal volume at a given temperature and pressure. Amedeo Avogadro, an Italian chemist and physicist, first described the law in 1811.
At 0 °C and 1 abm pressure, the molar volume of all ideal gases is 22.4 litres. If a gas's temperature and pressure remain constant, its volume will also grow as its amount increases.
If a gas's pressure and temperature are both constant, its volume falls as its volume of gas does. Every time you blow a balloon up, you demonstrate Avogadro's Law.
Therefore, Avogadro's Law is stated mathematically as follows: Vn=k, where V is the volume of the gas, n is the number of moles of the gas, and k is a proportionality constant.
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The English system is used as the International System of Measurement. Please select the best answer from the choices provided T F
Latent heat of vaporization is used to (1 Point) (a) overcome the forces of attraction between molecules in solid-state. (b) increase the kinetic energy of molecules in a liquid state. (c) overcome the forces of attraction between molecules in a liquid state. (d) increase the kinetic energy of molecules in the vapour state.
Answer:
Not sure what the answer is
Explanation:
I did this a while ago and dont remember sorry
what are the steps to go from the names of compounds to the formulas
Answer:
Explanation:
write down the formulas, use the expressions and formulas to convert
What is the answer to this I need help please
Answer : The boron-11 isotope is the most abundant.
Explanation :
As we are given that:
Average atomic mass of boron = 10.81 amu
Mass of boron-10 = 10.0129 amu
Mass of boron-11 = 11.0093 amu
As we know that the average atomic mass of an element is always closest to the most abundant isotope.
Out of the two boron isotopes, B-11 is closest in mass to the weighted average. Therefore, it is the most abundant.
Hence, the boron-11 isotope is the most abundant.
In the reaction, HCl + H2O produces H3O + Cl, what is the conjugate acid
Answer:
Conjugate acid is H3O
Explanation:
HCl + H2O = H3O + Cl
HCl = H+ and Cl- = Acid
H2O = OH- and H+ = Neutral as equal OH- and H+
H3O = H3O+ = Acid also known as Hydronium
Cl = Just free floating Chlorine = Cl-
Conjugate acid is H3O
Acid = A solution with more H+ ions than OH- ions.
a student is asked to draw an atom of sulfur on a board. the pictures below represents what the student drew. what is wrong with this sulfur atom
plzzzz help i need to finish up
A. Element
B. Compound
C homogenous mixture
D heterogenous mixture
Need help on #1 thank youu!
Answer:
Oil---> Wood---> Water
Explanation:
Denser things always go on bottom. Since oil is on top is the least dense among those, and then comes wood and then finally water.
