in the box next to your answer.
(b) Complete the sentence by putting a cross
An atom of an element always contains
D A
more protons than neutrons
B equal numbers of protons and neutrons
oc
more electrons than protons
D equal numbers of protons and electrons
Answer:
D equal numbers of protons and electrons
Explanation:
An atom of an element will always contain equal number of protons and electrons.
Atoms are electrically neutral because the number of positive charges and negative charges within them are always equal.
An atom is the smallest indivisible particles of an element that takes part in a chemical reaction. The positively charged particles within an atom are the protons. The negatively charged particles within an atom are the electrons.For;
So number of protons = number of electrons within an atom.
A wave has a wavelength of 1.2 m and frequency of 3 Hz what is the wave speed
Answer:
Speed of wave = 3.6 m/s
Explanation:
Given data:
Wavelength of wave = 1.2 m
Frequency = 3 Hz
Speed of wave = ?
Solution:
Formula:
Speed of wave = wavelength × frequency
by putting values,
Speed of wave = 1.2 m × 3s⁻¹ (Hz = s⁻¹)
Speed of wave = 3.6 m/s
A gas occupies 50.0mL at a standard temp. What volume would it occupy at 335 Celsius with
the pressure unchanged?
Answer:
V₂ = 111.3 mL
Explanation:
Given data:
Initial volume of gas = 50.0 mL
Initial temperature = standard = 273.15 K
Final volume = ?
Final temperature = 335 °C (335+273.15 = 608.15 K)
Solution:
The given problem will be solve through the Charles Law.
According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.
Mathematical expression:
V₁/T₁ = V₂/T₂
Now we will put the values in formula.
V₁/T₁ = V₂/T₂
V₂ = V₁T₂/T₁
V₂ = 50.0 mL ×608.15 K / 273.15 k
V₂ = 30407.5 mL.K / 273.15 K
V₂ = 111.3 mL
2. Why should a magnesium ribbon be cleaned before burning in air ?
Answer:
Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.
what's the formula mass of barium iodide
Answer:
BaI2
Explanation:
The number of valence electrons in sodium is/are
a 1
b 4
C2
d 3
Answer:
4
Explanation:
When electricity passes through water (H20), the water breaks down to form
hydrogen gas (H2) and oxygen gas (02).
Which equation represents this chemical reaction?
A.2H20+ 02 – 2H2
B.2H2 + 02 – 2H20
C.2H20 + 2H2 – 02
D.2H20 - 2H2 + O2
Answer:
A. Because you have to simplify
Answer:
decomposition
Explanation:
i dont cap
2. How does the particle motion of a gas affect its macroscopic behavior?
Answer: Particles in all states of matter are in constant motion and this is very rapid at room temperature. A rise in temperature increases the kinetic energy and speed of particles; it does not weaken the forces between them. ... Individual particles in liquids and gases have no fixed positions and move chaotically.
HOPE THIS HELPS
Why do scientists need a universal system to classify organisms?
Answer:
classification enables scientists to explain the relationships between organisms, which is helpful in trying to reconstruct the evolutionary roots of a particular species. Finally, taxonomic names provide unique descriptive names for organisms. This is sometimes an issue with common names of animals.
Explanation:
Found in the Internet
which of the following gas samples would have the largest volume, if all samples are at the same temperature and pressure?
A. 0.498 moles CO2
B. 19.91 grams of Ar
C. 3 x 10^ 23 molecules of H2
D. They would all have the same volume
Answer:
C. 3 x 10^ 23 molecules of H2
Explanation:
Please help!!
If u know any please tell!?
Answer: 176 g N2O, 72 g H2O
Explanation:
1. 64g O2 * (1 mol O2)/(32 g O2) * (2 mol N2O)/(1 mol O2) * (44g N2O)/(1 mol N2O) = 176 g N2O
2. 32g CH4 * ( 1 mol CH4)/(16 g CH4) * (2 mol H2O)/(1 mol CH4) * (18 g H2O)/(1 mol H2O) = 72 g H2O
What is the name of the piece of paper at the end of a chromatography experiment?
Answer:
There are two phases involved in chromatography; the 'stationary phase', in this case the paper, and the 'mobile phase', the salt solution. Sort the 'Smarties' into piles of the same colour.
Explanation:
can someone right my lab report for mee
A gas has a volume of 25.0 mL when under a pressure of 525 Maggie. What is the new pressure when the volume has been increased to 86.2 mL while temperature remains constant?
The new pressure when the volume has been increased : 152.26 mmHg
Further explanationGiven
V₁ = 25 ml
P₁ = 525 Maggie ? (maybe you mean mmHg)
V₂ = 86.2 ml
Required
The new pressure
Solution
Boyle's Law
At a constant temperature, the gas volume is inversely proportional to the pressure applied
[tex]\rm p_1V_1=p_2.V_2\\\\\dfrac{p_1}{p_2}=\dfrac{V_2}{V_1}[/tex]
[tex]\tt P_2=\dfrac{P_1.V_1}{V_2}\\\\P_2=\dfrac{525~mmHg\times 25~ml}{86.2~ml}\\\\P_2=152.26~mmHg[/tex]
What causes lightning? (2 points)
a
Build up of electric charges in the clouds
b
Flow of electric charges among clouds
c
Light energy created in the clouds
d
Reflection of light by the clouds
Answer: As static charge builds up in a storm cloud, the electric field surrounding the cloud becomes ... plasma and the cloud discharges itself to the Earth through a lightning strike. ... These two mechanisms are believed to be the primary causes of the ... The contact point between ground charge and cloud charge rapidly ascends ...
Explanation:The updraft carries the super-cooled cloud droplets and very small ice crystals ... The differences in the movement of the precipitation cause collisions to occur. ... positively charged and the graupel becomes negatively charged (Figure 2). ... but important positive charge buildup near the bottom of the thunderstorm cloud due ...
Answer:
a
Explanation:
Describe subscripts in chemical equations.
When an electron falls from an excited state to ground state, is energy released or absorbed?
Answer:
Energy is released.
Explanation:
When an electron absorbs energy, it moves up into an excited state. When it releases energy, it will return to the ground state.
Please help quick what’s the name of the starting position of a wave in science I really need an answer fast please!
Answer:
It starts at zero, and travels to the other side. Once it reaches the other fixed point, the wave travels back to the starting poing, this is represented as the lighter line. Notice the point right in the middle at p. This point is called a node.
Explanation:
Which object has the greatest inertia
Answer:
D
Explanation:
lighter objects have higher inertia
PLSS HELP! The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (4 points)
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.
Answer:
A. Carbon and oxygen are chemically bonded in it.
Explanation:
I saw someone with the exact question and they said A so yea ♥
How many mL are in 0.024 quarts (qt)
Answer:
99898
Explanation:
How do the properties of compounds compare to the properties of elements from which they are made
Answer:
When elements combine in a chemical reaction to form compounds, their individual identity is lost. Thus, the properties of elements change when they form chemical bonds with other elements to form compounds. For example, the compound water is made up of water and hydrogen.
Why h2o has higher boiling point than nh3
Answer:
H2O molecules are thus able to form an average of 4 H-bonds. H2O has a higher boiling point than NH3 because (i) the H-bonds are stronger and (ii) it contains twice as many H-bonds. H2O has a higher boiling point than HF because it contains twice as many H- bonds, despite these being individually weaker.
Explanation:
hope this is helpful
Lab: Acids and Bases Assignment: Lab Report
What is the purpose of the lab, the importance of the topic, and the question you are trying to answer?
What is your hypothesis (or hypotheses) for this experiment?
What methods are you using to test this (or each) hypothesis?
Section II: Data and Observations
Locate the data and observations collected in your lab guide. What are the key results? How would you best summarize the data to relate your findings?
Do you have quantitative data (numerical results or calculations)? Do you have qualitative data (written observations and descriptions)? How can you organize this date for your report?
Section III: Analysis and Discussion
What do the key results indicate?
If you constructed graphs, what trends do they indicate in your data?
Were there any problems with the experiment or the methods? Did you have any surprising results?
Section IV: Conclusions
What do the results tell you about your hypothesis(es)?
How do the data support your claim above?
If you could repeat the experiment and make it better, what would you do differently and why?
Answer:
Lab: Acids and Bases Assignment: Lab Report
The main point is to help the scientific method and to also see how it works.Sometimes people refer to the tentative answer as "an educated guess." Keep in mind, though, that the hypothesis also has to be testable since the next step is to do an experiment to determine whether or not the hypothesis is right! A hypothesis leads to one or more predictions that can be tested by experimenting.>State the hypotheses. Every hypothesis test requires the analyst to state a null hypothesis and an alternative hypothesis. The hypotheses are stated in such a way that they are mutually exclusive. That is, if one is true, the other must be false; and vice versa.>Formulate an analysis plan. The analysis plan describes how to use sample data to accept or reject the null hypothesis. It should specify the following elements.>Analyze sample data.Using sample data, perform computations called for in the analysis plan.>Interpret the results. If the sample findings are unlikely, given the null hypothesis, the researcher rejects the null hypothesis. Typically, this involves comparing the P-value to the significance level, and rejecting the null hypothesis when the P-value is less than the significance level and etc.Section II: Data and Observations
In a lab guide, the key results are those that support my working hypotheses or serve to reject these assumptions. Moreover, the key results may also be other discoveries that are important to understand the processes and/or mechanisms investigated in the experiment.•?
Section III: Analysis and Discussion
Key Results are the measures and milestones that indicate how you know you will accomplish our Objective.A linear pattern is a continuous decrease or increase in numbers over time. On a graph, this data appears as a straight line angled diagonally up or down (the angle may be steep or shallow). So the trend either can be upward or downward.Yes, i was surprised and learn so much and it was no problem.Section IV: Conclusions
Results will tell you which hypothesis is true.describe specific part of the procedure.If I were able to repeat the lab and do it differently I would try to do two different things to improve it. I would try to create the model in a simpler manner that allowed me to better see how the erosion factored in. I would also try to take more detailed notes on it if I were to repeat it.i hope it's helpAnswer:
anyone know the section II answers for a lab like this but its the thermal energy transfer lab
Explanation:
^^
(URGENT PLS HELP) Identical plants were grown in identical conditions, except one received fertilizer and water, while the other received only water.
Which best describes why the experiment either can be replicated or not replicated?
A.) The experiment can be replicated because the results were indicated.
B.) The experiment can be replicated because both plants had identical conditions.
C.) The experiment can not be replicated because no two plants are exactly the same.
D.) The experiment can not be replicated because the methods are not fully explained
Answer: It would be D, it can not be replicated becuz the methods are different. one plant had water and fertilizer, while the other only had water. You cannot replicate it you will have different outcomes because of the methods. I hope this helps you the answer is D
Explanation:
Answer:
personally I do not think that the experiment can be replicated and if it is replicated they might not get the same result.
Explanation:
It depends on how much fertilizer they used and since plants are different it might give different results. I know this isn't going to help you but go with your gut.
A photon of green light strikes an unknown metal and an electron is emitted. The voltage is set to 2 volts. The electron cannot make the journey to the second plate. What can be said about a similar experiment done with violet light? A. An electron may or may not be emitted in the second experiment. It cannot be determined. B. An electron will be emitted in the second experiment, but it cannot be determined whether it will reach the second plate. C. An electron will be emitted in the second experiment, and it will make it to the second plate. D. An electron will not be emitted in the second experiment.
Answer:
The correct answer is:
An electron will be emitted in the second experiment, but it cannot be determined whether it will reach the second plate.
Explanation:
In fact, violet has higher frequency than green light. This means that photons on violet carry more energy than photons of green light (remember that the energy of a photon is proportional to it's frequency:
[tex]e = hf[/tex]
, so when they hit the surface of the metal, more energy is transferred to the electrons. The electron was already emitted with green light, so it must be emitted with also violet light, given the more energy transferred.
Compare the amount of current used by a 750-W microwave oven and a 1000-W microwave oven if they both operate in a 120-V circuit.
Answer:
The current used by the 750-W microwave is 0.75 times the current used by the 1,000-W microwave
Explanation:
The given parameters are;
The electrical power of one of the microwaves, P₁ = 750 W
The electrical power of the other microwave , P₂ = 1,000 W
The applied voltage of the circuit = 120-V
Electric power, P = I·V
Where;
I = The amount of current used
V = The applied voltage = 120 V
Therefore, for the first microwave, we have;
P₁ = I₁ × V
∴ I₁ = P₁/V = 750 W/(120-V) = 25/4 amperes = 6.25 amperes
The amount of current used by the 750-W microwave, I₁ = 6.25 amperes
For the second microwave, we have;
P₂ = I₂ × V
∴ I₂ = P₂/V = 1,000 W/(120-V) = 25/3 amperes = 8.[tex]\overline 3[/tex] amperes
The amount of current used by the 1,000-W microwave, I₂ = 8.[tex]\overline 3[/tex] amperes.
The ratio of the two currents, is I₂/I = (25/3 amperes)/(25/4 amperes) = 4/3
Therefore, I₂ = 4/3 × I₁, from which we have;
I₁ = 3/4·I₂
The current used by the 750-W microwave is 3/4 the current used by the 1,000-W microwave.
Which is not a property of an Acid?
A) low pH
B) Bitter
C) Burning Effects
D) Sour
Answer:
b bitter
Explanation: can i have brainlist please
The molar mass of NaCl is 58.44 g/mol. What is the molarity of a solution that
contains 120 g of NaCl in 0.750 L of solution?
0.649 M
3.00 M
2.74 M
2.05 M
Which is a statement of the second law of thermodynamics?
O A. Entropy tends to increase in a system.
O B. Molecular motion stops at absolute zero.
O C. The net reaction rate is zero at equilibrium.
O D. Energy cannot be created or destroyed.
Answer:
A: Entropy tends to increase in a system
Which is a statement of the second law of thermodynamics?
O A. Entropy tends to increase in a system.
O B. Molecular motion stops at absolute zero.
O C. The net reaction rate is zero at equilibrium.
O D. Energy cannot be created or destroyed.
ITS A
