Answer:
40 electrons
Explanation:
The element of zirconium (Zr) has an atomic number of 40, which means it has 40 protons and 40 electrons. It also has a molar mass of 91.224 g/mol.
Choose the best tool for each scenario.
Identifying a trend in temperature change over time:
graph
Measuring the mass of a product of a chemical reaction:
Answer:
a) Graph
b) Weight balance or gas syringe or upside-down measuring cylinder
Explanation:
a) Identifying a trend in temperature change over time - The best tool for this scenario is to represents the temperature daily, weekly, monthly or annually on graph to interpret the fluctuation in temperature owing to local seasonal changes and weather conditions
b) Measuring the mass of a product of a chemical reaction - If the product is solid or liquid then the balance is used to measure the mass. If the product is a gas, then gas syringe or upside-down measuring cylinder is used.
Please help, only a couple of days left!!!
Answer:
the heat from the universe during the big bang
a.k.a.
ITS A
Explanation:
the universe is still expanding, so what is gonna be used to create that new matter that's expanding the universe? energy and heat from the beginning of the universe! the universe started off as this point that was probably smaller than a quantum foam and infinite heat and started expanding from there
A. 2 pts: In terms of conservation of mass, what were the results of each experiment (which one conserved mass and which one did not)?
B. 4 pts: PROVIDE a SPECIFIC explanation for "why" the results in both videos were different.
. 2 pts: Discuss differences in the experimental steps between the two videos (for example what was done in video one that was not done in
video two, why would this make a difference in conserving mass?)
• 2 pts: Look at both chemical equations (below for convenience), what difference in the type of products would have contributed to the
differences in why one conserved mass and one did not?
REACTION 1: Pb(NO3)2 (aq) + 2K1 (aq) --> 2KNO3 (aq) +Pölz (s)
• REACTION 2: NaHCO3(s) + CH3COOH(aq) → CO2(g) + H2Om + CH3COONa(aq)
Answer:
dftdffdgxrdfdrdxxxxdddddddddddddeeertdffddy
Find the surface area of a square pyramid with side length 5 cm and slant height 4 cm.
Answer:
h = height
s = slant height
a = side length
P = perimeter of base
e = lateral edge length
r = a/2
V = volume
L = lateral surface area
B = base surface area
A = total surface area
Explanation:
Volume of a square pyramid:
V = (1/3)a2h
Slant Height of a square pyramid:
By the pythagorean theorem we know that
s2 = r2 + h2
since r = a/2
s2 = (1/4)a2 + h2, and
s = √(h2 + (1/4)a2)
This is also the height of a triangle side
Lateral Surface Area of a square pyramid (4 isosceles triangles):
For the isosceles triangle Area = (1/2)Base x Height. Our base is side length a and for this calculation our height for the triangle is slant height s. With 4 sides we need to multiply by 4.
L = 4 x (1/2)as = 2as = 2a√(h2 + (1/4)a2)
Squaring the 2 to get it back inside the radical,
L = a√(a2 + 4h2)
Base Surface Area of a square pyramid (square):
B = a2
Total Surface Area of a square pyramid:
A = L + B = a2 + a√(a2 + 4h2))
A = a(a + √(a2 + 4h2))
Una reacción química es un proceso en el cual se produce un cambio químico, es decir, se consume una o más sustancias a medida que se forman una o más sustancias nuevas.
Answer:
Para ser mas exactos una reaccion quimica es donde los reactivos se transforman en productos.
Explanation:
Durante las reacciones quimicas, ocurren ciertas transformaciones que hace que se tome o se libere energia del medio, generando que los reactivos de la reaccion, es decir los compuestos iniciales, en un determinado espacio y tiempo bajo ciertas condiciones de presion y temperatura exactas se transformen en productos.
Para la quimica, la misma cantidad de materia que se encuentra en los reactivos se mantendra en los productos, es por eso que cada reaccion quimica debe respetar las reglas de la estequiometria y estar balanceadas a la perfeccion.
A solution (HELP ASSAAAAP ROAD TO GRADUATION)
Question 7 options:
A)
can contain more than two phases.
B)
must contain water.
C)
is always a liquid.
D)
is a single-phase homogeneous mixture.
Hey there! A simple explanation is below.
Answer:
D) is a single phase homogeneous mixture.
Explanation:
A solution is a form of homogenous combination made up of two or more components in chemistry. A solute is a material that is dissolved in another material, known as a solvent, in such a combination. The mixing of a solution takes place at a scale where the effects of chemical polarity are present, resulting in solvation-specific interactions. In most cases, the solution is in the condition of the solvent, because it is most common in the mixture.
How many moles of sodium are in its 85 g?
Answer:
22.98977
Explanation:
don't worry about that
Explanation:
85 g Na × (1 mol Na/22.9898 g Na)
= 3.7 mol Na
A polar commercial antacid contains both Al(OH)3 and Mg(OH)2. Are these compounds Arrhenius bases, Brønsted-Lowry based, or both? Explain your answer.
Answer:
Magnesium hydroxide, Mg(OH)2, is an Arrhenius base and therefore also a Brønsted-Lowry base.
However, water can also act as a base by accepting a proton from an acid to become its conjugate base, H3O+. where Al(OH)3 is acting as a Lewis Base.
Explanation:
Arrhenius acids and bases
An Arrhenius acid is any species that increases the concentration of H+start text, H, end text, start superscript, plus, end superscript in aqueous solution.
An Arrhenius base is any species that increases the concentration of OH−start text, O, H, end text, start superscript, minus, end superscript in aqueous solution.
Which two factors are leading to an increased use of natural resources?
A + 2 B + 4 C → products is known to be second order in A, first order in B and independent of the concentration of C. What is the value of the rate constant for this reaction if its rate is 0.783 M · s−1 when [A] = 5.00 M, [B] = 7.00 M, and [C] = 3.00 M? −2 −1 Answerinunitsof M ·s .
Answer:
4.47 × 10⁻³ M⁻² s⁻¹
Explanation:
Let's consider the following generic equation.
A + 2 B + 4 C → products
This reaction is known to be second order in A, first order in B and independent of the concentration of C (zero order in C). The rate law is:
rate = k × [A]² × [B] × [C]⁰
rate = k × [A]² × [B]
where k is the rate constant
When the rate is 0.783 M/s, [A] = 5.00 M, [B] = 7.00 M, and [C] = 3.00 M, the rate constant is:
k = rate / [A]² × [B]
k = 0.783 M/s / (5.00)² × (7.00) = 4.47 × 10⁻³ M⁻² s⁻¹
Briefly explain why adding insulation to an attic helps reduce heating costs.
Answer:
Insulation reduces the exchange of heat through a surface such as a wall, attic, duct or roof. In a well-insulated home, less warm air escapes from the house during the winter, and less cool air escapes during the summer, reducing the amount of energy needed for heating and cooling
What happens when an unstable nucleus undergoes radioactive decay?
A. Electrons change energy levels to balance the nucleus.
B. Energy is absorbed by the nucleus to make it more stable.
O C. Particles or electromagnetic radiation are emitted.
D. The nucleus increases in mass through radioactive decay.
WHAT HAPPENS WHEN ELECTRIC CURRENT PASSES THROUGH ACIDIFIED WATER.
Answer:
When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode
Which of the following could possibly be true about a strong acid? (Check all that apply:).
It will completely dissociate (break apart) when dissolved in water.
It could have a pH of 6
It could have a pH of 13
Only a few of the acid molecules will dissociate (break apart).
It could have a pH of 2.
It could have a pH of 9
Answer:
it could have a pH of 2 it will completely dissociate when dissolved in waterSodium-22 has a 2.605-year half-life. If you begin with 1.570 grams of Na-22, how many grams are left after 1.00 year?
Type the correct answer in the box. Express your answer to the correct number of significant figures.
Answer:
1.20 grams
Explanation:
Correct on edmentum/plato
Answer: 1.20 grams
Explanation:
A flexible container has 5.00 L of nitrogen gas at 298 K. If the temperature is increased to 333 K, what will be the new volume of that sample of nitrogen?
0.179 L
0.223 L
4.47 L
5.59 L
Answer:
5.59 L
Points earned on this question: 4
Explanation:
took the test
The new volume of the sample of gas when the temperature is increased from 298 K to 333 K is 5.59 L
Charles' lawCharles' law states as follow:
V₁ / T₁ = V₂ / T₂
Where
V₁ is the initial volume T₁ is the initial temperature V₂ is the new volume T₂ is the new temperature How to determine the new volumeFrom the question given above, the following data were obtained
Initial volume (V₁) = 5 LInitial temperature (T₁) = 298 KNew temperature (T₂) = 333 KNew Volume (V₂) =?V₁ / T₁ = V₂ / T₂
5 / 298 = V₂ / 333
Cross multiply
298 × V₂ = 5 × 333
Divide both side by 298
V₂ = (5 × 333) / 298
V₂ = 5.59 L
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4. What is a renewable resource? List some examples.
Answer:
Renewable resources include biomass energy (such as ethanol), hydropower, geothermal power, wind energy, and solar energy. Biomass refers to organic material from plants or animals. This includes wood, sewage, and ethanol (which comes from corn or other plants).
five examples of renewable resources
Solar energy.
Wind energy.
Geothermal energy.
Hydropower.
Bioenergy.
I hope it help you
Answer:
The most popular renewable energy sources
currently are
Solar energy
Wind energy
Hydro energy
Tidal energy
Geothermal energy
Biomass energy
How much heat is required to raise the temperature of 20.0g of ice from-12°C to 0°C?
Answer:
https://socratic.org/questions/how-much-heat-is-required-to-convert-5-88-g-of-ice-at-12-0-c-to-water-at-25-0-c-
Explanation:
How are liquid water, ice, water different from each other?
Answer: In liquid water, water molecules are moving faster. They are still close together, but they are no longer stuck in a rigid pattern as they are in ice. Water molecules in liquid water are constantly sliding past and bumping into each other; they keep moving from one place to another.
Answer:
they are different forms
Explanation:
ice is solid
and water is liquid
they also have different densities
an engineer chooses to use bamboo as a building material because it grows quickly and needs little space to grow. This is an example of?
Answer:
A) This is an example of Green Design
Explanation:
Besides Mars, what other bodies in our solar system are considered the most likely places for the discovery of some form of life? Explain
Answer:
Europa
Explanation:
it is though that to have a subsurface liquid of water
Answer:
Europa, Venus, And Proxima B.
Explanation:
Europa is a moon which is known to have a subsurface liquid of water. Venus can also be inhabited due to it being almost the same size as Earth, and having many common features with earth. Such as; Metal core in the interior of the planet, along with a rocky mantle. Its atmosphere is mainly made up of nitrogen and carbon dioxide. Although humans can't breathe in carbon dioxide, it is a similarity the planets have and I'm sure scientists can make an invention making carbon dioxide into oxygen. Proxima B can also be inhabited in. It is a newly discovered planet and has many of the same features as Earth. It has water, leafy plants, and is close to a star so the temperature is not extremely hot; neither cold.Which of the following best describes an electron transition?
A. An electron gains or loses energy and moves between continuous
energy levels.
B. An electron gains or loses charge and changes into a proton or a
neutron.
C. An electron gains or loses energy and moves between quantized
energy levels.
D. An atom gains or loses an electron and becomes an ion.
Answer:
A. An electron gains or loses energy and moves between continuous
energy levels.
Joelle is a manager at a construction company, and she is interested in the chemistry behind the materials they use. She has begun studying the materials used to fill walls. She knows that to keep the temperature inside a room steady the material must be a thermal insulator, and she predicts that materials should not be acidic or else they would dissolve too easily in water.
Which of these is a molecular ingredient that could be used in a wall-filling material ?
C27H36N2O10
Na6Ba6
NeNa
HCl
Answer:
a
Explanation:
A molecular ingredient that could be used in a wall-filling material is C₂₇H₃₆N₂O₁₀, is not a good thermal insulator, hence option A is correct.
The big molecule C₂₇H₃₆N₂O₁₀ is a poor thermal insulator. Since NeNa is a relatively reactive chemical, it would probably dissolve in water far too quickly. The acidic molecule HCl would dissolve far too quickly in water.
Not a good thermal insulator is C₂₇H₃₆N₂O₁₀. It is a big molecule composed of a lot of hydrogen atoms. Since hydrogen atoms are excellent heat conductors, they would be ineffective in stopping heat from passing through a material used to fill a wall.
Thus, the option (A) C₂₇H₃₆N₂O₁₀ is correct.
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Which defines the word planet?
A. A large body that revolves around the Moon.
B. A large body suitable for life.
C. A large body that contains water and land.
D. A large body that revolves around the Sun.
Answer:
I think it's D cause one of the requirements for a planet is that it has to revolve around a star
What does the symbol 2CO represent in the model below? 2CO + o^2 -> 2CO2
Answer:2CO (g) + O2 (g) 2CO2 (g)This Equation Means That No Matter How Much Carbon Monoxide And Oxygen ... Question: 2CO (g) + O2 (g) 2CO2 (g)This Equation Means That No Matter How Much Carbon Monoxide And Oxygen Gas Is Added To The Flask, Only 2 Moles Of CO And 1 Mole Of O2 Will React To Make Two Moles Of Co2.What Is Wrong With This Statement?
Explanation:
Answer: a reactant
Explanation: online physics class
What is the delta H when 72.0 grams H2O condenses at 100.00C?
Here are some constants that you MAY need.
specific heats heat of fusion heat of vaporization
H2O(s) = 2.1 J/g0C 6.01 kJ/mole 40.7 kJ/mole
H2O(L) = 4.18 J/g0C
H2O(g) = 1.7 J/g0C
2930 kJ
163 kJ
-163 kJ
-2930 kJ
Answer: The value of [tex]\Delta H[/tex] is -163 kJZ
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
We are given:
Given mass of water = 72.0 g
Molar mass of water = 18 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of water}=\frac{72.0g}{18g/mol}\\\\\text{Moles of water}=4mol[/tex]
Calculating the heat released for the condensation process:
[tex]\Delta H=n\times \Delta H_{(vap)}[/tex] ......(2)
where,
[tex]\Delta H[/tex] = amount of heat released
n = number of moles of water = 4 moles
[tex]\Delta H_{(vap)}[/tex] = specific heat of vaporization = -40.7 kJ/mol
Negative sign represents the amount of heat released.
Putting values in equation 2:
[tex]\Delta H=4mol\times (-40.7kJ/mol)=-163kJ[/tex]
Hence, the value of [tex]\Delta H[/tex] is -163 kJ
Which of the following statements is correct about electrical insulators?
A. They do not contain any atoms.
B. Their protons are not allowed to move about freely.
C. The electrons are not able to move about freely.
D. They are good at conducting heat only.
Answer:
the answer is C in my opinion.. hope this might be helpful
What is the pH of a solution?
O A. A measure of the strength of the acid
B. A measure of the buffering ability of the solution
O c. A measure of the hydrogen gas concentration
O D. A measure of the acidity of the solution
Answer:
D. A measure of the acidity of the solution
Explanation:
pH is a measure of how acidic or basic a solution is, and is measured on a scale from 0-14, where 7 is neutral, anything less than 7 is acidic, and anything more than 7 is basic.
During nuclear fission and fusion, what is matter that seems to disappear actually converted into?
mass
energy
volume
nuclei
Answer:
The Correct Answer is " Energy"
Goodluck Guys
Explanation:
During nuclear fission and fusion, what is matter that seems to disappear actually converted into energy and the correct option is option 2.
What is Nuclear fission and Fusion?
here are two types of nuclear reactions called nuclear fission and nuclear fusion. These nuclear reactions involve the disintegration and combination of the elemental nucleus.
Nuclear fission refers to the breaking or splitting of a large or parent atom into smaller ones, or two or more daughter atoms.
The term 'nuclear fusion' refers to the process by which two or more atoms combine to form a larger atom. The nuclear fusion process is endothermic because it requires absorbing energy to fuse two atoms.
Both fission and fusion are nuclear reactions that produce energy.
Therefore, During nuclear fission and fusion, what is matter that seems to disappear actually converted into energy and the correct option is option 2.
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Which question would most likely be studied by a biologist?
A.
How can a drug that treats cancer be synthesized?
B.
How can cancer-causing substances be regulated?
C.
How much ultraviolet radiation passes through the atmosphere?
D.
What causes cancer cells to grow uncontrollably?
Answer:
The correct answer would be - D. What causes cancer cells to grow uncontrollably?
Explanation:
A Biologist is a person that studies living organisms and the study of living organisms and their process called biology. Biology is a very vast field that involves many branches such as zoology, botany, biochemistry, immunology, biophysics, anatomy, ecology and many more.
So, given all are can be an example of the study biology wanted to do, however, the question most likely studied by a biologist would be What causes cancer cells to grow uncontrollably as it deals with an organism and their biological process.
