Answer:
The answer is C) Gravity keeps all matter on Earth.
Explanation:
I took the test and this was correct!
(Not a fake answer like some, I promise!)
Choose all the answers that apply. Which of the following energy forms are involved in a nuclear power plant?
1)heat
2)mechanical
3)electrical
4)nuclear
Answer:Three mutual conversions of energy forms occur at nuclear power plants: nuclear energy is converted into thermal energy, thermal energy is converted into mechanical energy, and mechanical energy is converted into electric energy.
Explanation:
Sort each of the following elements by effective nuclear charge, Zeff, from smallest to largest:
Sn, Rb, Sb, In, and Sr
Answer:
Rb = +1 , Sr = +2, In= +3, Sn = +4, Sb= +5
Explanation:
Formula:
Zeff = Z - S
Z = atomic number
S = number of core shell or inner shell electrons
For Sn:
Electronic configuration:
Sn₅₀ = [Kr] 4d¹⁰ 5s² 5p²
Zeff = Z - S
Zeff = 50 - 46
Zeff = +4
For Rb:
Electronic configuration:
Rb₃₇ = [Kr] 5s¹
Zeff = Z - S
Zeff = 37 - 36
Zeff = +1
For Sb:
Electronic configuration:
Sb₅₁ = [Kr] 4d¹⁰ 5s² 5p³
Zeff = Z - S
Zeff = 51 - 46
Zeff = +5
For In:
Electronic configuration:
In₄₉ = [Kr] 4d¹⁰ 5s² 5p¹
Zeff = Z - S
Zeff = 49 - 46
Zeff = +3
For Sr:
Electronic configuration:
Sr₃₈= [Kr] 5s²
Zeff = Z - S
Zeff = 38 - 36
Zeff = +2
The reversible reaction, 2NO{g) ⇌ N2 (g) + O2 (g), would be classified as a __________________ reaction.
homogeneous
heterogeneous
endothermic
*
2. Which of the following is an example of mass?
O A. 7 cm3 of air in a balloon
B. 1 mL of water in a test tube
O C. 4 centimeter piece of string
D. 8 kilograms of bananas
stions and Problems What is the freezing point of Salol?
Answer:
106.7 degrees f
Explanation:
The density of two liquids, A and B, are 1000. kg/m3 and 600. kg/m3, respectively. The two liquids are mixed in a certain proportion and the density of the resulting liquid is 850 kg/m3. How much of liquid B (in grams) does 1.0 kg of the mixture contain? Assume the volume of the two liquids is additive when mixed.
Answer:
Mass of liquid B = 271.2 gram
Explanation:
Given:
Density of liquid A = 1000 kg/m³
Density of liquid B = 600 kg/m³
Density of mixture = 850 kg/m³
Mass of mixture = 1 kg
Assume:
Volume of liquid A = Va
Volume of liquid B = Vb
So,
Volume of mixture = Va + Vb
Mass of liquid A = 1000(Va)
Mass of liquid B = 600(Vb)
Mass of mixture = Mass of liquid A + Mass of liquid B
1 = 1000(Va) + 600(Vb)
Volume of mixture = 1 / 850
So,
(1/850) = Va + Vb
Vb = (1/850) - Va
1 = 1000(Va) + 600[(1/850) - Va]
Va = 7.25 × 10⁻⁴
Vb = (1/850) - Va
Vb = (1/850) - [7.25 × 10⁻⁴]
Vb = 4.25 × 10⁻⁴
Mass of liquid B = 600(Vb)
Mass of liquid B = 600(4.25 × 10⁻⁴)
Mass of liquid B = 271.2 gram
The mass of liquid B in the 1 Kg mixture is 300 g
Let the volume of liquid A be Va
Let the volume of liquid B be Vb
From the question given above, the following data were obtained:
Density of liquid A = 1000 kg/m³
Density of liquid B = 600 kg/m³
Density of mixture = 850 kg/m³
Mass of mixture = 1 kg
Mass of Liquid B (in grams) =? Next, we shall determine the mass of liquid A and BFor Liquid A:
Density of liquid A = 1000 kg/m³
Volume of liquid A = Va
Mass of Liquid A =?
Mass = Density × Volume
Mass of Liquid A = 1000 × Va
Mass of liquid A = 1000(Va)For Liquid B:
Density of liquid B = 600 kg/m³
Volume of liquid B= Va
Mass of Liquid B =?Mass = Density × Volume
Mass of Liquid B = 600 × Va
Mass of liquid B = 600(Vb)Next, we shall determine the volume of the mixture.Density of mixture = 850 kg/m³
Mass of mixture = 1 kg
Volume of mixture =?Volume = mass /density
Volume of mixture = 1 / 850
Volume of mixture = 0.0012 m³Next, we shall determine the volume of liquid AMass of mixture = 1 Kg
Mass of mixture = Mass of liquid A + Mass of liquid B
1 = 1000(Va) + 600(Vb) ....... (1)Volume of mixture = Va + Vb
Volume of mixture = 0.0012 m³
Thus,
0.0012 = Va + Vb
Vb = 0.0012 – Va ........ (2)Substitute Vb in equation 2 into equation (1)
1 = 1000(Va) + 600[0.0012 – Va]
1 = 1000Va + 0.72 – 600Va
Collect like terms
1 – 0.72 = 1000Va – 600Va
0.28 = 400Va
Divide both side by 400
Va = 0.28 / 400
Va = 0.0007 m³Next, we shall determine the volume of the liquid BVolume of mixture = 0.0012 m³
Volume of liquid A (Va) = 0.0007 m³
Volume of liquid B (Vb) =?Vb = 0.0012 – Va
Vb = 0.0012 – 0.0007
Vb = 0.0005 m³Finally, we shall determine the mass of liquid BVolume of liquid B (Vb) = 0.0005 m³
Mass of liquid B = 600(Vb)
Mass of liquid B = 600(0.0005)
Mass of liquid B = 0.3 Kg
Multiply by 1000 to express in grams
Mass of liquid B = 0.3 × 1000
Mass of liquid B = 300 gLearn more: https://brainly.com/question/17769713
which element would be used to help support a building
C
He
Na
Fe
12 PTS!! WILL GIVE BRAINLIEST!! DUE TODAY!!
The experiment is increasing and decreasing the amount of predators, pollution, and food to see how the cricket frogs will react.
Test variable (independent variable):
Outcome variable (dependent variable):
Control group:
Answer:
Test variable (independent variable): Predators, Pollution, Food.Outcome variable (dependent variable): Cricket Frogs.Control group: Beginning Frog Count
Explanation:
If pollution isincreased, then the cricket frog population will (stay the same) over the span offive years.If the amount of food available isincreased, then the cricket frog population will (increase) overthe span of five years.Procedure:The procedures are listed in your virtual lab. You do not need to repeat them here. Please be sureto identify the test variable (independent variable), outcome variable (dependent variable), andcontrol group for this experiment.
7. A cyclist starting from rest accelerates at a rate of 6 m/s until she reaches 30 m/s. How long
does it take her to accelerate?
Answer:
Explanation:
The given values are:
a= 6m/s²
u= 0 m/s
v = 30 m/s
t= ?
The formula is :
[tex]a=\frac{v-u}{t}[/tex]
thus,
[tex]t=\frac{v-u}{a}\\t=\frac{30-0}{6}\\t= 5 seconds[/tex]
Question 14
4 pts
Using the formula Na + Cl2 --> Naci, if 2.98 moles of sodium are combined with
excess" chlorine, how many moles of sodium chloride will be made? Note that in
this question, excess means extra or as much as you need.
Answer:
2.98 moles of NaCl are produced.
Explanation:
Given data:
Moles of sodium = 2.98 mol
Amount of chlorine = excess
Moles of NaCl produced = ?
Solution:
Chemical equation:
2Na + Cl₂ → 2NaCl
Now we will compare the moles of sodium chloride with only sodium because sodium is limiting reactant and chlorine is in excess thus sodium limit the yield of product.
Na : NaCl
2 : 2
2.98 : 2.98
2.98 moles of NaCl are produced.
One of the physical properties of bases is that they ____.
Question 17 options:
taste sour
feel slippery
crumble
corrode metal
Answer:
feel slippery
Explanation:they physical properties are due to its slippery nature when touched
How is volume calculated given mass and density? (4 points)
A. Sum of mass and density
B. Mass divided by density
C. Mass multiplied by density
D. Difference of mass and density
Which two particles are found in an atom's nucleus?
O A. Neutrons
O B. Electrons
O C. Protons
O D. Isotopes
Answer:
protons and neutrons so A and C
What ionic substance is being used to illustrate the concept of lattice energy in Model 1?
Answer:
magnesium oxide
Explanation:
hope this helps
which is not possible sign of chemical change
A:color change
B:light given off
C:heat given off
D:a change of state
Answer:
A. color change
Explanation:
changing the color of a metal does not change its physical properties.
hope it helps.
4. Do you think the distribution of elements 10 billion years from now
will be different than it is today? Why or why not?
Answer:
yes
Explanation:
everything will change
Which unit of size are the smallest organisms found on Earth?
millimeters
picometers
nanometers
micrometers
Answer:
it is nanometers the third one
Explanation:
hope this helps
The correct answer is:
(D) Micrometers
Hope this helps!
Kinds of matter with label and example
Answer:
Liquid: water
Solid: Rocks
Gas: Air
Explanation:
Danielle is asked to determine the density and the identity of a metal. She determines the mass of the metal to be 102.06g and then determines the volume of the sample using water displacement. Find the density. Round the answer to the nearest whole number?
Answer:
11 g/mL
Explanation:
From the question given above, the following data were obtained:
Mass of metal = 102.06 g
Volume of water = 38 mL
Volume of water + metal = 47 mL
Density of metal =.?
Next, we shall determine the volume of the metal. This can be obtained as shown below:
Volume of water = 38 mL
Volume of water + metal = 47 mL
Volume of metal =..?
Volume of metal = (Volume of water + metal) – (Volume of water)
Volume of metal = 47 – 38
Volume of metal = 9 mL
Finally, we shall determine the density of the metal as follow:
Mass of metal = 102.06 g
Volume of metal = 9 mL
Density of metal =.?
Density = mass /volume
Density of metal = 102.06 / 9
Density of metal = 11.34 ≈ 11 g/mL
Therefore, the density of the metal is 11 g/mL
Mintu wants to increase the heat transfer between a metal iron and another piece of metal he wants to shape. He decides to increase the time the two metals are in contact, use a larger metal iron, and use a new metal material with a higher specific heat.
Where is Mintu's error?
Answer:
Mintu should chosen a material with a lower specific heat
Explanation:
I got the answer right on the test trust me it is correct
PLEASE HELP ME ASAP!!!!!! i hope you can see this!!! if you do this can you please show your work
Answer:
3.83%
Explanation:
First, find the average of the measured value. You should get 286.
291 + 287 + 295 + 281 = 1154
1154/4 = 288.5
Subtract the accepted value (300) from the average measured value (286). Take the absolute value of your answer. You should get 14.
288.5 - 300 = -11.5 = 11.5
Divide the difference from the above problem (14) by the accepted value (300). You should get 0.0467.
11.5/300 = 0.0383
Multiply by 100%.
0.0383 × 100% = 3.83%
The percent error is 3.83%.
Answer:
3.83 percent
Explanation:
Accepted Value = 300 degrees celsius
So since we are given the formula for percentage error,
we know that we have to find the average measured value since the accepted value is already provided
Average Measured Value:
Sum of all measured values / number of measured values
(291 + 287 + 295 + 281) / 4
1154 / 4
288.5 degrees celsius
Now, plugging the values in the given formula:
(average measured value - accepted value) *100 / accepted value
(288.5 - 300) * 100 / 300
-1150 / 300
-3.83 percent
Taking Absolute Value:
3.83 percent
Hence, the average value of the temperature is 3.83 percent less than the accepted value
What is a hypothesis? O a part of the scientific method that is not necessary a specific and testable question O the variables I observe during the experiment HELP HELP PLS PLS PLS HELP NoW NowWWwWw I'll mark u BRAINLIEST!!!!!!!!
Which answer below correctly identifies the type of change and the explination for the boiling of water
How many elements are in a isotope?
Answer:i believe 9-?
Explanation:
boron-10
boron-11
carbon-12
carbon-13
oxygen-16
oxygen-17
oxygen-18
chlorine-35
chlorine-37
What will an object moving at a constant velocity do?
come to a stop, unless it is pushed by another force
A.increase in speed
B.maintain a constant velocity until acted on by another force
C.come to a stop on its own
Answer:B
Explanation: an object in motion will stay in motion until acted on by another force and an object in rest will stay in test until acted on by another force
are there more metals or nonmetals on the periodic table?
Answer:yes
Explanation:
I think so
There are more metals than nonmetals on the periodic table. The majority of elements on the periodic table are metals, which are found on the left and middle sections of the periodic table.
Metals typically have properties such as high electrical and thermal conductivity, luster, malleability, and ductility.
Nonmetals, on the other hand, are found on the right-hand side of the periodic table, along with the noble gases. Nonmetals generally have properties opposite to those of metals, such as poor electrical and thermal conductivity and a lack of metallic luster. There are fewer nonmetals compared to metals on the periodic table.
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N2(g) + 2H(g) -> N2 H4(g) What are the volumes of N2 gas and H2 gas required to form 28.5 grams of N2 H4 at 30'C and 1.50 atm?
Answer:
Volume of N₂ = 14.76 L
Volume of H₂ = 29.52 L
Explanation:
Given data:
Mass of N₂H₄ formed = 28.5 g
Pressure = 1.50 atm
Temperature = 30°C (30+273 = 303 k)
Volume of N₂ and H₂ needed = ?
Solution:
Chemical equation:
N₂ + 2H₂ → N₂H₄
Number of moles of N₂H₄ formed = mass/ molar mass
Number of moles of N₂H₄ formed = 28.5 g/ 32 g/mol
Number of moles of N₂H₄ formed = 0.89 mol
Now we will compare the moles of N₂H₄ with N₂ and H₂ form balance chemical equation.
N₂H₄ : N₂
1 : 1
0.89 : 0.89
N₂H₄ : H₂
1 : 2
0.89 : 2×0.89 = 1.78 mol
Volume of H₂:
PV = nRT
1.50 atm × V = 1.78 mol × 0.0821 atm.L/mol.K × 303 K
V = 44.28atm.L /1.50 atm
V = 29.52 L
Volume of N₂:
PV = nRT
1.50 atm × V = 0.89 mol × 0.0821 atm.L/mol.K × 303 K
V = 22.14 atm.L /1.50 atm
V = 14.76 L
Which of the following is a characteristic differentiating tropical and temperate rainforests?
a. the location
b. the types of trees
c. the average temperature
d. all of the answers are correct
Answer:
D. all of the answers are correct
Explanation:
edge 2020
Rainforests are defined by the evergreen and canopy trees. The tropical and temperate rainforests differ in the locations, type of plantation, and temperature. Thus, option d is correct.
What is a tropical and temperate rainforests?Tropical and temperate rainforests are rainforests that differ from each other based on various factors. The tropical rainforest is located at the latitude near the equator, between the Tropic of Cancer and Capricorn. They are covered with canopied trees and average warm temperature conditions.
On the other hand, the temperate rainforests are found away from the Equator near the north side of the tropics and are marked by the presence of coniferous or broadleaf trees. They have a cooler climate and two seasons.
Therefore, option d. the tropical and temperate rainforests have different temperatures, locations, and trees.
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Your big brother has been bragging about how he can bench press 4,000 grams at the gym. Sounds impressive, but you know better. Use your skills to find how many pounds of weight he is actually pressing.
A brother is bragging about doing a bench press of 4000 grams at the gym. 4000 grams is equal to 8.818 pounds.
What is a bench press?The bench press or chest press is training or weight training to strengthen your arm and chest muscles. It is done by laying down on a bench and pushing and pulling up the bars with weight.
It is a common weight-lifting exercise in gyms. Trainers use accordingly weight on the basis of the trainee's weight and strength that is doing the bench press, and the weight is measured differently in different countries. Eight-pound is not a very big amount.
In America, weight is measured in pounds, one kg is 1000 grams and
1 gram is 0.00220462
4000 x 0.00220462
4000 grams will be 8.818 pounds.
Thus, 4000 grams is equal to 8.818 pounds.
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30 points!!! please help chem question
Answer: below -45
Explanation: