Answer: Lithium (Li)
Explanation:
Once it loses its only valence electron, there’s no longer a negative charge.
Write the beta decay equation for the following isotope: 91 38 Sr? Please write out steps
Answer:
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}Y[/tex]
Explanation:
The unbalanced nuclear equation is
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e \, + \, ?[/tex]
Let's write the question mark as a nuclear symbol.
[tex]\rm _{38}^{91}Se} \longrightarrow \, _{-1}^{0}e \, + \, _{Z}^{A}X[/tex]
The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.
Then
98 = 0 + A, so A = 98 - 0 = 98, and
38 = -1 + Z, so Z = 38 + 1 = 39
Then, your nuclear equation becomes
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}X[/tex]
Element 39 is yttrium, so the balanced nuclear equation is
[tex]\rm _{38}^{91}Sr \longrightarrow \, _{-1}^{0}e + \, _{39}^{91}Y[/tex]
Why would the pressure of a sample of gas at a constant volume fall .10 atm?
Answer:
As the temperature of a sample of gas falls from 45.0ºC to 30.0ºC, its pressure falls to 300.
Explanation:
's A pitcher contains 1 gallon of
lemonade. All of the lemonade will be
poured into 4 empty glasses. If an equal
amount is poured into each glass, how
much lemonade will be in the first glass?
Answer:
1 quart of lemonade will be in the first cup
Explanation:
1/4th of a gallon is a quart
What Le Chatelier’s factors cause an increase in the concentration of Hb(CO)4(aq) in the Hb(CO)4(aq) + 4O2(g)Hb(O2)4(aq) + 4CO(g)
Answer:
Explanation:
Hb(CO)4(aq) + 4O2(g) ⇄ Hb(O2)4(aq) + 4CO(g)
1 ) If we increase the concentration of CO(g) , the reaction above will proceed in reverse direction to decrease its concentration, according to Le Chatelier principle. Hence more of Hb(CO)4(aq) will be formed.
2 ) If we decrease the concentration of O₂ , then also , reaction will proceed in reverse direction . Hence concentration of Hb(CO)4(aq) will be increased .
Consider a system of four gases. The equilibrium concentration of each product is 2.3 M and the equilibrium concentrations of the reactants are equal. The equilibrium is shown here:
A + B C + D K = 2.6
What is the equilibrium concentration of gas A?
Answer:
The equilibrium concentration of gas A is 1.43 M
Explanation:
Here we have the reaction expressed as follows;
A + B → C + D and
The formula for equilibrium constant is therefore presented as follows;
[tex]K = \frac{[C]\times [D]}{[A]\times [B]}[/tex]
Where:
[C] = [D] = 2.3 M
[A] = [B]
K = 2.6
Hence, we have;
[tex]2.6 = \frac{2.3\times 2.3}{[A]\times [A]} = \frac{5.29}{[A]^2}[/tex]
[tex][A]^2= \frac{5.29}{2.6} = 2.03[/tex]
[A] = 1.43 M
The equilibrium concentration of gas A = 1.43 M.
Answer:
The equilibrium concentration of gas A = 1.43 M
Explanation:
First set up the equilibrium expression:
[tex]K = \frac{[C]\times [D]}{[A]\times [B]}[/tex]
The problem states that each product has a concentration of 2.3M at equilibrium, and that k=2.6
We also know that [A] and [B] are the same.
Since we are solving for [A] I'm going to change [A][B] to A²
[tex]2.6 =\frac{2.3^2}{A^2}[/tex]
Now we just need to solve for A²
A² = 5.29 / 2.6
A² = 2.0346
A = √2.0346
A = 1.43
Therefore, the equilibrium concentration of gas A = 1.43 M.
Why were scientists surprised to find coal in the arctic?
Answer:
coal is made from compressed plant matter and how exactly did plants grow on the surface of an ocean. (as there is no land mass beneath the arctic.)
Explanation:
it would be like finding a fly in an ice cube to simplify it.
They were surprised to find coal in arctic because ordinarily coal was supposed to be found in warm or hot environments and not cold region like the arctic.
The arctic is located at the far northern part of the world which is characterized by its extreme cold weather.
A limited vegetation of plants such as grasses, mosses and lichens are found in this region irrespective of the extreme cold weather through out the year.
Coal is a type of fuel gotten from fossils and deposits of plant vegetation.
Scientist has discovered that continents do move over time through a process called continental drift. This is the reason why limited vegetaion is found in the arctic leading to the formation of coal.
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How are electrons similar and different to the planet Earth?
Answer:
The planets themselves are composed of several trillions or quadrillions or more atoms. As far as hard science is concerned, it would be really hard to picture them as electrons. Conclusion: It can be said with a great accuracy that our planets are NOT huge electrons.
Rutherford's experiments showed that the mass of atoms was mostly concentrated in a very small region, with charge equal to the atomic number- the nucleus. He absolutely did not show, nor is it true, that electrons orbit the nucleus as if they were planets. That was a guess people made in trying to figure out how to picture the atom.
(Hope this helps) Sky
3. Trees, bananas, skateboards and pancakes are all solids. They have
atoms that are closely packed together and don't move around very
much. Solids also have definite shape, mass and volume. "Definite"
means that it doesn't easily change. When you pour cereal into a bowl,
the pieces of cereal don't change shape. But when you pour milk into a
bowl, the milk takes the shape of the bowl. That's because cereal is a
solid.
A
Which of the following is an example of a solid?
A. applesauce
Corange juice
B. watermelon
D. berry smoothie
Answer:
B. Watermelon
Explanation:
Watermelon is the only option with a definite shape that wouldn't change if you put it in a bowl
Which is usually associated with a faster reaction rate?
A. diluting a solution of the reactants
B. adding modeling clay to the reactants
C. removing heat energy from the reactants
D. using a solid with a high surface area in the reactants
Answer:
D. using a solid with a high surface area in the reactants, is your correct answer.
Explanation:
Using a solid with a high surface area in the reactants is usually associated with a higher reaction rate.
Why is wind named from where the wind is blowing from?
Winds are always named from the direction it blows from
Uneven heating of Earth's surface,in turn,causes differences in air pressure at various locations. Heated air rises,creating an area of low pressure beneath. Cooler air descends, creating an area of high pressure
What causes a molecule to have a net dipole moment?
A. The presence of only nonpolar bonds in the molecule
B. The presence of Van der Waals forces
C. The presence of a net charge that does not cancel out
D. The presence of both covalent and ionic bonds in the molecule
Answer:
Option C
Explanation:
Dipole moment being ac vector quantity has both magnitude and direction. All bonding forces have dipole moment ranging from partially positive to negative moment.
Net dipole moment is the dipole moment arising after summation of all the existing dipole moments. On the basis of dipole moment it is determined whether the molecule is polar or non polar.
Hence, option c is correct
Answer:c
Explanation:
Which of the following units could not be used to measure density?
O A. Kilograms per liter (kg/L)
B. Grams per milliliter (g/mL)
C. Pounds per cubic inch (lb/in)
D. Grams per cubic centimeter (g/cm3)
Answer: Pounds per Cubic inch(lb/in3)
balance the following equation:
!!!!
Answer:
CaC2 + 2H2O > C2H2 + Ca(OH)2
Explanation:
Count the amounts of Ca, C, H, and O, all separately on both sides.
Ca: 1 Ca: 1
C: 2 C:2
H: 2 H: 4
O: 1 O: 2
Now, your goal is to get both sides equal to each other by adding a 2 in front of H2O.
The amplitude of a wave is the vertical distance from the midpoint to either the crest or the
trough of the wave
True
False
High levels of carbon dioxide in the blood trigger which of the following responses in the body?
Select one:
a decrease in the production of sweat
a decrease in the speed of the pulse
an increase in the rate of breathing
an increase in the rate of digestion
What slows down heat energy from escaping the Earth?
Answer:
Greenhouse gases such as carbon dioxide and water vapor make an atmosphere around the earth and make less heat escape
Explanation:
Identifying Ways Rocks Change in the Rock Cycle Cycle of a rock. Arrows point from one stage to the next. Stage A, small, brown granules, to Compaction and cementation or Stage C. Arrow labeled Heat and pressure from Stage C to B, larger gray rocks. Arrow labeled Melting from Stage B to Magma. Arrow labeled Cooling from Magma to Igneous Rock. Arrow labeled Melting from Igneous Rock to Magma. Stage D arrows from Igneous Rock to Stage A, from Stage B to A, and from Stage C to A. Using the drop-down menus, label the parts of the rock cycle.
A- sediment, sedimentary rock, or metamorphic rock
B- sediment, sedimentary rock, or metamorphic rock
C- sediment, sedimentary rock or metamorphic rock
D- compaction and cementation, heat and pressure, or weathering and erosion
Answer:
sediment, metamorphic rock, sedimentary rock, weathering and erosion
Explanation:
for edge 2020
hope this helps
HAVE A GREAT DAY : )
Sediment, sedimentary rock, or metamorphic rock are the parts of the rock cycle. Therefore, the correct option is option A.
What are sedimentary rock, and metamorphic rock?Sedimentary rocks are created by the aggregation or deposition of organic or mineral particles at the Earth's surface, following by cementation. Sedimentation refers to the mechanisms that lead these grains to settle in situ.
Any of a family of rocks formed by the modification of pre - existing rocks in reaction to changing environmental circumstances, such as temperature, pressure, or mechanical stress, as well as the addition or deletion of chemical components is metamorphic rock. Sediment, sedimentary rock, or metamorphic rock are the parts of the rock cycle.
Therefore, the correct option is option A.
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what is an example of a strong base?
HCl
NaCl
NaOH
HF
Answer:
The answer is NaOH
Explanation:
Strong bases are characterized by the fact that they dissociate completely in an aqueous solution. In this case, sodium hydroxide, NaOH, is classified as a strong base because it dissociates completely in an aqueous solution to form sodium cations, Na+, and hydroxide anions, OH−. Also, it is strong because it totally breaks in its ion. And the base which breaks totally in its atom called the strong base and which doesn't it that is a weak base.
Answer:
NaOH
Explanation:
Got it right in the test. Please mark as brainliest
I just need the answer please to both if you can
Answer:
No.4 is B No.5 is d
Explanation:
Answer:
Q 4: d
Explanation: this is all I can answer
What improvements have been made in modern farming? Select all that apply.
1. machines can do more work over less time
2. better seeds sprout and grow much more quickly
3. trains can transport food over long distances faster
4. trains can transport the machines to rural farms once built
5. insecticides used to keep insects off the crops
Answer:
all of them except number 2
Explanation:
Answer:
1,3,4,5 the other perosn is correct
Explanation: That what my quiz said
I need an answer ASAP!!
Answer:
C:
Explanation:
Current flows from negative to positive.So the electrons will be moving left.
when a current is applied, positive charged copper ions (called cations) leave the anode (positive electrode) and move to the cathode (negative electrode).
Adding concentrated
sulfuric acid to sugar
What reaction is this?
Answer:
Dehydration of Sugar
Explanation:
I AM GIVING BRAINLIEST PLEASEE HELPPPP I NEED HELPPPPPP PLEAEEEEEE
63.2 g of BaCl 2 are dissolved in enough water to make a 634 mL solution. What is the molarity?
Answer:
0.479 M or mol/L
Explanation:
So Molarity is moles/litres of solution...often written as M=mol/L
So here we are given grams of BaCl2 which we have to convert to moles. To convert to moles of BaCl2 we have to divide 63.2 g BaCl2 by molar mass of BaCl2 which is 208.23 g/mol so you get 63.2/208.23 = 0.3035 moles of BaCl2
Second step is converting the 634mL to litres by simply dividing by 1000 because we know 1 litre has 1000ml so 634/1000 = 0.634L
Now we just plug these guys in our molarity formula M=mol/L
M= 0.3035/0.634 = 0.479 M or mol/L
Answer:
Interestingly enough, I'm not getting
0.0341% w/v
either. Here's why.
Start by calculating the percent composition of chlorine,
Cl
, in calcium chloride, This will help you calculate the mass of chloride anions,
Cl
−
, present in your sample.
To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that
1
mole of calcium chloride contains
2
moles of chlorine atoms.
2
×
35.453
g mol
−
1
110.98
g mol
−
1
⋅
100
%
=
63.89% Cl
This means that for every
100 g
of calcium chloride, you get
63.89 g
of chlorine.
As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every
100 g
of calcium chloride, you get
63.89 g
of chloride anions,
Cl
−
.
This implies that your sample contains
0.543
g CaCl
2
⋅
63.89 g Cl
−
100
g CaCl
2
=
0.3469 g Cl
−
Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in
100 mL
of this solution.
Since you know that
500 mL
of solution contain
0.3469 g
of chloride anions, you can say that
100 mL
of solution will contain
100
mL solution
⋅
0.3469 g Cl
−
500
mL solution
=
0.06938 g Cl
−
Therefore, you can say that the mass by volume percent concentration of chloride anions will be
% m/v = 0.069% Cl
−
−−−−−−−−−−−−−−−−−−−
I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.
.
Explanation:
Calculate the molarity of a KCl solution if 37.3 g of KCl are dissolved in water to give a
final solution volume of 500 ml.
The molarity of a KCl solution if 37.3 g of KCl are dissolved in water to give a final solution volume of 500 ml is 1 M.
What is Molarity?Molarity of a given solution is known as the total number of moles of solute per litre of the solution. A solution that is 1.00 molar (written 1.00 M) contains 1.00 mole of solute for every liter of solution.
Molarity = (No. of moles of solute ÷ Volume of solution in liters)
The unit of molarity is mol L⁻¹.
Molarity is temperature dependent because as temperature changes, volume of the solution also changes.
Given, Mass of KCl = 37.3 g
Molar mass of KCl = 74.5 g/mol
Volume of solution = 500ml = 0.5 L
No. of moles = Mass / Molar mass = 0.5
Molarity = 0.5/0.5 = 1 M
Therefore, The molarity of a KCl solution if 37.3 g of KCl are dissolved in water to give a final solution volume of 500 ml is 1 M.
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An ideal gas, such as helium, is in a sealed container made of hard steel. If the container is heated, what would happen to the gas trapped inside the container?
Group of answer choices
The volume of the gas will decrease
The pressure of the gas will increase
The volume of the gas will increase
The pressure of the gas will decrease
Answer:
The correct answer is The pressure of the gas will increase
The volume of the gas will increase
Explanation:
Step 1: Data given
The gas in a container is heated, this means the temperature increases
Suppose we start with a temperature of 100 K and a pressure of 1 atm and a volume of 1L
Step 2:
V1/T1= V2/T2
⇒V1 = the initial volume = 1L
⇒T1 = the initial temperature = 100 K
⇒V2 = the new volume = TO BE DETERMINED
⇒T2 = the increased temperature = 200 K
1/100 = V2 / 200
V2 = 2 L
This means when the temperature increases, the volume will increase
P1/T1 = P2/T2
⇒P1 = the initial pressure = 1 atm
⇒T1 = the initial temperature = 100 K
⇒P2 = the new pressure = TO BE DETERMINED
⇒T2 = the increased temperature = 200 K
1/100 = P2 / 200
P2 = 2 atm
This means when the temperature increases, the pressure will increase
The correct answer is The pressure of the gas will increase
The volume of the gas will increase
Which of the following presents a safety hazard while working in the science laboratory?
A knowing how to use equipment
B wearing safety goggles
C following directions
D working alone
Answer:
D working alone
Explanation:
Working alone is the only option that could potentially be a safety hazard; if you have no one watching your back, errors could occur, like dropping glass or burning your hand, and no one is around to help you.
Choices A, B, and C are not correct because those are all good safety standards.
Which statement best describes liquid water and water vapor at equilibrium?
A. Liquid water stops entering the gas phase.
O B. The concentration of liquid water equals the concentration of
water vapor.
C. The concentrations of liquid water and water vapor are stable.
D. The concentration of liquid water is zero.
C. The concentrations of liquid water and water vapor are stable. it describes the fact that liquid water and water vapor are at equilibrium.
EquilibriumAn equilibrium is achieved when no more water vapor can enter into the gas phase from the liquid water during evaporation process. This happens when a saturation is attained between liquid water and the vapor phase.Hence, option (c) is correct. The concentration of liquid water and water vapor will become stable.
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What is the molarity of a solution in which 0.45 grams of sodium nitrate (NaNO3) are dissolved in 265mL of the solution?
A. 29.8M
B. 87.2M
C. 0.02M
D. 0.52M
Answer:
M=0.02
Explanation:
85 g NaNO3 -> 1 mol NaNO3
0.45 g NaNO3 ->x
x=(0.45 g NaNO3 * 1 mol NaNO3)/85 g NaNO3 x= 5.3 x 10^-3 mol
265 mL= 0.265 L
M= mol solute/ L solution
M= 5.3 x 10^-3 mol NaNO3/0.265 L M=0.02
A curved piece of glass or other transparent material that is used to refract light is called a (an) _____.
A) mirror
B) lens
C) reflector
D) optical fiber
Answer:
Lens
A curved piece of glass or other transparent material that is used to refract light.
Explanation:
u got ig?
A curved piece of glass or other transparent material that is used to refract light is called a lens. The correct option is B).
What are lenses?A curved piece of transparent material, such as glass, that bends light is called a lens. A lens's shape and the object's position both affect the kind of image it produces.
The center of a concave lens is thinner than the edges. Bent glass is defined as glass that has been curved or bent into a convex or concave shape. The desired shape is created by gently heating the glass until it becomes pliable, then molding it into that shape.
Light is refracted through lenses. When a light beam enters a lens, it is refracted; then, when it leaves the lens, it is refracted once more.
Therefore, the correct option is the B) lens.
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A weather forecast shows 35 m/h on the weather map. Which weather component does this number represent?
A.Humidity
B. Precipitation
C.Wind direction
D.Wind speed
Answer:
D. Wind Speed
Explanation:
When the question brings up 35 m/h, the m/h stands for Miles per Hour. What option can you measure the miles per hour. Here's a hint, it applies to cars as well when cops give your parents speeding tickets. Miles per Hour = Speed. So, you are measuring the wind speed.
