Answer:
Formation of a dative bond or coordinate bond between ammonia and boron trifluoride. When the nitrogen donates a pair of electrons to share with the boron, the boron gains an octet. Both atoms are electronically saturated.
Explanation:
Identify the number of significant figures in each of these measurements of an object length: a. 76.48 cm b. 76.47 cm c. 76.59 cm
All of the measurements have 4
The number of significant figures in each of these measurements of an object's length: a. 4 b. 4 c. 4.
What are significant figures?The significant figures are the digits or numbers from zero to nine which are used to signify and specify the reporting of the measurement having uncertain digits.
Starting zero is not significant, decimal is not significant, ending zero after the decimal is significant and ending zero before and without decimal is not significant.
Therefore, a. 76.48 cm = 4 b. 76.47 cm c. = 4 76.59 cm = 4 are the number of significant figures in each of these measurements of an object's length.
Learn more about significant figures, here:
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What is the parent isotope when Cl-33 is formed during a beta decay?
Answer:
33/16 S
Explanation:
In beta decay, the atomic number of the daughter nucleus increases by one unit while the mass of the daughter nucleus remains the same as that of the parent nucleus.
Hence, if we know that a beta decay has occurred, then the parent nucleus must have the same mass as its daughter nucleus but have an atomic number that is less than that of the daughter nucleus by only one unit, hence the answer above.
Convert 205 L to ul.
Answer: 205000000 microliter
Hope this helps!
Answer:
2.05 x 10⁸ uL
205000000 uL
Explanation:
Step 1: Find the conversion
1 liter (L) = 1 x 10⁶ microliters (uL)
Step 2: Set up dimensional analysis
[tex]205 L(\frac{1(10)^6uL}{1L} )[/tex]
Step 3: Multiply and cancel out units
Liters and Liter cancel out.
We are left with uL
205(1 x 10⁶) = 2.05 x 10⁸ uL or 205000000 uL
Water flows over Niagara Falls at the average rate of 2,400,000 kg/s, and the average height of the falls is about 50 m. Knowing that the gravitational potential energy of falling water per second = mass (kg) × height (m) × gravity (9.8 m/s2), what is the power of Niagara Falls? How many 15 W LED light bulbs could it power?
Answer:
The power of Niagara falls is 1,176 Mega Watts
The number of 15 Watt bulbs it can power is 8,400,000 bulbs
Explanation:
The rate at which the water falls given as the mass flow rate = 2,400,000 kg/s
The height from which the water falls = 50 m
The gravitational potential energy (potential energy PE.) of falling water = Mass (kg) × height (m) × gravity (9.8 m/s²)
The mass of water that falls per second = 2,400,000 kg
PE. = 2,400,000 kg × 50 m × 9.8 m/s² = 1,176,000,000 Joules
The power = The rate at which the energy is generated = The amount in kg of water that fall from the height per second × The height × Acceleration due to gravity
The power = 2,400,000 kg/s × 50 m × 9.8 m/s² = 1,176,000,000 Watts
The power of Niagara falls = 1,176,000,000 Watts = 1,176 Mega Watts
The number of 15 Watt bulbs it can power = 1,176,000,000/15 = 78,400,000 bulbs
The number of 15 Watt bulbs it can power = 8,400,000 bulbs.
An airplane travels 2100 km at 1000km/hE. It encounters a wind and slows to 800 km/h E for the next 1300 km. What is the average velocity of the airplane for this trip?
Answer:
The average velocity of the airplane for this trip is 1684.21 km/h
Explanation:
Average velocity is the rate of change of displacement with time. That is,
Average velocity = [tex]\frac{Displacement }{Change in time}[/tex] = Δx / Δt = [tex]\frac{x2 - x1}{t2 - t1}[/tex]
Now we will calculate the time taken by the airplane for the first motion before it encounters a wind.
From,
Velocity = [tex]\frac{Distance traveled}{Time taken}[/tex]
Time = [tex]\frac{Distance traveled}{Velocity}[/tex]
Therefore, Time = [tex]\frac{2100km }{1000km/h}[/tex]
Time = 2.1h
This is the time taken before the airplane encounters a wind.
Hence, t1 = 2.1h
Now, For the time taken by the airplane when it encounters a wind
Also from,
Velocity = [tex]\frac{Distance traveled}{Time taken}[/tex]
Time = [tex]\frac{Distance traveled}{Velocity}[/tex]
Therefore, Time = [tex]\frac{1300km }{800km/h}[/tex]
Time = 1.625h
Hence, t2 = 1.625h
Now, to calculate the average velocity
Average velocity = [tex]\frac{x2 - x1}{t2 - t1}[/tex]
x1= 2100, x2= 1300, t1= 2.1h and t2= 1.625h
Hence, Average velocity = [tex]\frac{1300 - 2100}{1.625 - 2.1}[/tex]
Average velocity = 1684.21 km/h
Which term represents the movement of molecules from an area of lower concentration to one of higher concentration with carrier molecules, using energy?
Answer:
Active transport
Explanation:
Active transport is defined as the movement of ions or molecules from a region of lower concentration into a region of higher concentration by the use of energy. Two examples of active transport include the uptake of glucose in human intestine and the absorption of mineral ions into plant roots.
Active transport requires energy because it involves the movement of molecules against an existing concentration gradient.
Which statement best explains why the overall charge on an atom is zero? The positive charge of the neutrons in the nucleus equals the negative charge in the electron cloud. The positive charge of the protons in the nucleus equals the negative charge in the electron cloud. The negative charge of the neutrons in the nucleus equals the positive charge in the electron cloud. The negative charge of the protons in the nucleus equals the positive charge in the electron cloud.
the positive charge of the neutrons in the nucleus equals the negative charge in the electron cloud
Answer:
B on egde
Explanation:
Three models of atomic theory are illustrated in the image. Place them in chronological order.
A)
A, B, C
B)
BAC
CAB
D)
CBA
Justin B. Believes that the temperature lowering during the fall months is what causes the color of the leaves to change. He set up an experiment wherein he placed some plants in 80 degrees rooms and some in 60 degree rooms. He observed the color of the leaves for a total of 1 month. At the end of the month Justin observed that 3/4 of the plants in the 60 degree temperature had begun to change colors and only 1/4 of the plants in the 80 degree temperature began to change colors.
Answer:
This question is incomplete, the remaining part of the question is:
What is the control group, independent variable and dependent variable?
Control group: Plants placed in 80 degree rooms
Independent variable: Change in temperature
Dependent variable: Change in color of leaves
Explanation:
The independent variable in a scientific experiment is the variable that the experimenter controls or manipulates in order to bring about a change in the dependent variable. In this experiment, the variable manipulated by Justin B is the TEMPERATURE CHANGE.
On the other hand, a variable is said to be dependent if it is the variable that responds to a change made to the independent variable or rather it is the outcome. In this experiment, Justin B is trying to see the outcome on the color change in leaves when exposed to a low temperature, hence, COLOR CHANGE IN LEAVES is the dependent variable.
Control group of an experiment is the group that receives no experimental treatment. It is the group the experimenter considers normal and hence is comparing with his experimental group. In this experiment, Justin B believes the leaves change color in a low temperature, hence, he placed some plants in a lower temperature (60 degree) in order to compare them with when the plants are placed in a higher temperature (80 degree). As far as this experiment is concerned, the plants placed in 80 degrees temperature are believed by Justin B not to undergo color change, hence, they are the CONTROL GROUP while the group he placed in 60 degrees temperature are what he is interested in, making them the EXPERIMENTAL GROUP
While doing a lab a student found the density of a piece of pure aluminum to be 2.85 g/cm3 the accepted value for the density of aluminum is 2.70 g/cm3. What was the percent error
Answer:
THE PERCENT ERROR IS 5.55 %
Explanation:
To calculate the percent error, we use the formula:
Percent error = Found value - accepted value / accepted value * 100
Found value = 2.85 g/cm3
Accepted value = 2.70 g/cm3
Solving for the percent error, we have:
Percent error = 2.85 g/cm3 - 2.70 g/cm3 / 2.70 g/cm3 * 100
Percent error = 0.15 / 2.70 * 100
Percent error = 0.05555 * 100
Percent error = 5.55 %
In conclusion, the percent error is 5.55 %
13. To refine aluminum from its ore, aluminum oxide is electrolyzed to form aluminum and oxygen. At which electrode does oxygen form?
O A. Both the anode and the cathode
OB. Anode
O C. Cathode
OD. Neither electrode
Answer:
I think B
Explanation:
Answer:
Anode
Explanation:
Which of the following questions cannot be answered by science? How does color of light affect the mating behaviors of bees? How does soil pH affect the productivity of fruit trees? How does temperature affect the amount of oxygen able to dissolve in water? How do contrasting colors affect the quality of a painting?
Answer: How do contrasting colors affect the quality of a painting
Answer:
The answer is D.
Explanation:
I just took the test. :)
Built from amino acids
carry out most of the life-sustaining functions of the human body
Answer:
proteins carry out most of the life sustaining functions of the human body
what are the fundamental particles of an atom
Protons, neutrons, and electrons are the fundamental subatomic particles.
Obtain the valence shell configuration of Al and S from their positions in the periodic table.
Answer:
Al: 3
S: 6
Explanation:
Al is in Group III. This means that it has 3 valence electrons.
S is in Group VI. This means that it has 6 valence electrons.
I hope this helps :)
which physical property of the alkali metal group decreases down the group
Answer:
Melting and boiling point
Explanation:
For all group 1 elements, the melting and boiling point of the various members of the group decreases down the group. Hence, as the elements become heavier, they tend to have lower melting and boiling points.
Thus in moving from lithium to francium, there is a steady decrease in the melting and boiling points of elements down the group.
When a high mass main sequence star runs out of both hydrogen and helium in its core, the core begins to fuse
Answer:
i guess it explodes
Explanation:
Answer:
carbon
Explanation:
How are the atoms
or molecules
arranged in solid?
Answer:
Gases, liquids and solids are all made up of atoms, molecules, and/or ions, but the behaviors of these particles differ in the three phases. ... gas are well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.
Hope this helped :)
What is 0.00034 in exponential form
Answer:
3.4 × 10 ^− 4
Explanation:
Move the decimal so there is one non-zero digit to the left of the decimal point. The number of decimal places you move will be the exponent on the
10 . If the decimal is being moved to the right, the exponent will be negative. If the decimal is being moved to the left, the exponent will be positive.
Explain the need of the term avarage atomic mass
Answer:
The average atomic mass of an element is the sum of the masses of its isotopes, each multiplied by its natural abundance (the decimal associated with percent of atoms of that element that are of a given isotopе). An element does not have an absolute atomic mass.
Hope this helps :)
A chemist adds two substances together in a beaker. When he combines the substances, a solid substance is formed. He filters the solid substance and measures its mass on an electronic balance. When the chemist measures the mass of the substance, he is A. collecting relevant data. B. devising a hypothesis. C. making a prediction. D. drawing a conclusion.
Answer:
collecting relevant data
Explanation:
got this answer from another website ;)
if 1/4 cups are in 1 serving jow many servings are in 4 cups
Answer:
One serving is 1/4 cup therefore 1 cup would be 4 servings. Since we have 9 cups we would then multiply 9 x 4 and the answer would be 36 servings. You have a ratio of cups to serving, so 1/4 cup : 1 serving, or .
Explanation:
Which has a larger density a large brick or a small brick? why?
Answer:
15.2
Explanation:
the chemical reaction in chemistry libretto texts.
Answer:
Neither
Explanation:
Density is independent of size. Basically, the density of an object isn't determined by it's size.
If two objects are made of the same exact material, they will have the same exact density, regardless of the size.
So, the large brick and the small brick will have the same density, as long as they are made from the same type of brick material.
Explain why the Bohr model was insufficient and how the quantum model explained this deficiency. How is the electron viewed differently in each model
Answer and Explanation:
Bohr's model of the atom defined the electron as a particle that orbits around the nucleus in only certain orbital levels. As a result, it couldn't readily give account of the energy levels of larger elements with high atomic number.
The quantum model of the atom however, approaches the electron in an atom as not just a particle but a wave, with its distinct quantum number per energy level. It can therefore give the position and speed of an electron simultaneously at any energy level.
I hope this explanation is sufficient.
3. Dorji was provided with four colourless solutions. He was asked to
identify the type of solution using universal indicator. Dorji's finding is
recorded in Table 8.5. Use the information from Table 8.5 to answer the
questions that follow.
Table 8.5.
Solution
COA
Colour change of universal indicator
Red
Blue
Purple
Yellow
en
i. What type of solutions are solution A and solution C?
ii. Which solutions do you think are:
a. acidic in nature?
b. basic in nature?
iii. What will happen if equal volume of solution B and solution D are
mixed?
Answer:
First, we can test Solution 1. We know that Sodium Hydroxide is a strong base. If we test acids on blue litmus paper, they will turn red. If we test bases on red litmus paper, they will turn blue. So, you can test all the of the solutions- water, sodium hydroxide and hydrochloric acid with blue and red litmus paper. HCl, Hydrochloric acid is an acid, so it will turn blue litmus paper red. It will not turn red litmus blue. The acids will turn blue litmus paper red. The bases will turn red litmus paper blue. Only water is a neutral liquid, which will not turn blue litmus paper red or red litmus paper blue. It will not change the colour of it. Thus, if you test all the solutions with blue and red litmus paper, you will know which solution is water. Water is the only one which is neutral. It is the only solution which cannot change the colour of any litmus paper. Thus, you can identify it very easily.
Example #2: Ajet is traveling at 80 m/s when it starts to approach
a runway. It is able to land and park in 10 s. What is its
acceleration?
Answer:
-8 m/s^2
Explanation:
The formula for acceleration is:
a= v^2 - v^1/t
a= acceleration
v^2- final velocity which in this case would be 0 since the jet comes to a stop.
v^1= original velocity which is 80 m/s.
t=time or 10s
Substitute the letters for the numbers and you get this:
a= 0 - 80/10
0 - 80= -80
-80 divided by 10 is -8.
Hope this helps! :)
Question 7
Which of the following discoveries led to the development of the quantum mechanical model?
A electrons occupied different energy levels around the nucleus
B
atoms of gases combined to form compounds in whole-number ratios
Cmost alpha particles passed through gold foil without hitting matter
D cathode rays could be bent by a magnetic field
In hot sunlight, dry sand heats up more than ocean water. What principles of heat and thermal energy does this difference demonstrate?
Answer:
1) Heat capacity
2) Thermal Conductivity
3) Heat reflection
Explanation:
The heat capacity of a body is the heat required to raise the temperature of the given mass of the body by 1° C.
The heat capacity = Mass × Specific heat capacity
Given that the mass of the ocean, which covers 70% of the Earth's surface has a much larger mass than a given unit of sand and that the specific heat capacity for the water (4,200 J/(kg·°C)) is much more than that of the sand (800 J/(kg·°C)), the heat required to raise the temperature of the mass of sand by 1°C is much less than the heat required to raise the temperature of the temperature of the ocean by 1°C
Therefore, the sand will have a higher temperature than the ocean when exposed to the same Sunlight
2) The ocean has a thermal conductivity of 0.5 W/(m·°C) the thermal conductivity of sand is 2.05 W/(m·°C), therefore, sand takes heat from the Sun faster than the ocean which also increases its temperature
3) The albedo, of the ocean is more than that of the sand so the ocean absorbs more of the Sun's heat than the sand but very little of the heat is conducted.
What are the number of protons, neutrons, and electrons in an atom of Tellurium- 129?
Answer:
Number of protons = 52, Number of electrons = 52, Number of neutrons = 76
Explanation:
What do you think the scientific question is for the
boiling water experiment
Answer:
Scientific Question: ... I will boil water and add a substance like salt to see if the boiling point increases.