Answer:
see the pict for the answers
Which statement best describes scientific laws? A) Scientific laws are scientists' opinions of why events occur. B) Scientific laws are facts that describe observed reoccurring natural events. C)Scientific laws explain why natural events occur. D) Scientific laws were theories that have been proven to be true.
Answer:
Option B and D seem to be correct
Explanation:
As a scientific law is a statement which is bases on repeated experimental observations that describes some aspects of nature and also they are were theories that have been proven to be true as a theory become a law when the experiment agree with the theory and no contrary opinions so according to my studies , B and D options are seems to be correct.
5) If an atom has a positive charge what is it called?
Answer:
An atom that has a negative or positive charge it is called an ion.
Answer:
It''s called a Cation
Explanation:
Susana heats up a sample of red crystals. While the sample is being heated,a gas is released and a blue powder is left after heating. Is the sample of red crystals an element or compound?
Answer & Explanation:
Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.
Answer:
Susana's red crystal sample is a compound because it was broken down into a gas and blue powder. It is not an element because elements cannot be broken down into simpler substances by ordinary means, such as heating.
Explanation
Sample response form Edg
Which of the following notations is the correct noble gas configuration for Li
Noble gas configuration for Li : [He]2s¹
Further explanationIn an atom, there are levels of energy in the shell and sub-shell
This energy level is expressed in the form of electron configurations.
Lithium with atomic number 3, then the electron configuration:
1s²2s¹
And for noble gas configuration or it can be called Condensed electron configurations :
[He]2s¹
Answer:
[He]2s¹
Explanation:
give 7 and example of how each wave in the EM spectrum in used in our daily lives
Four students are carrying out different laboratory procedures. Piroja is mixing baking soda and vinegar to see if it reacts. Jason is heating salt water over a burner until the water evaporates. Kali is putting crushed ice and ice cubes on a table to see which melts first. Francisco is separating iron filings from sand using a magnet. Which experiment relies on convection? Piroja’s experiment Jason’s experiment Kali’s experiment Francisco’s experiment
Answer: Jason experiment
Explanation:
I just took the test
Answer: Jason's Experiment
The ionization energies for removing successive electrons from sodium are 496 kJ/mol, 4562 kJ/mol,
6912 kJ/mol, and 9544 kJ/mol. The great jump in ionization energy after the first electron is removed
indicates that
Select one:
O a. sodium has four or five electrons.
O b. the atomic radius has increased.
c. a d-electron has been removed.
d. the noble gas configuration has been reached.
Answer:
D
Explanation:
The high jump of ionization energy indicates that we are trying to remove electron from noble gas configuration state.
The ionization energy data specifies that the Elements are from group 1 at period 3 or greater.
Removing the first electron require 496 kJ and the second ionization energy jump significantly due to the removal of electron from the noble gas configuration which is logical because electron try to maintain the especially stable state.
How do the alveoli in the lungs move oxygen and nutrients into the bloodstream? 1.Gravity 4.Time 2.Diffusion 5.Pressure 3.Magnetic force
Answer:
2.Diffusion
Explanation:
As we metabolize certain nutrients for the correct functioning of our cells, carbon dioxide is produced as a result. We need oxygen in order to metabolize them, so we need to have a system to incorporate it, and to eliminate the carbon dioxide produced.
This system is provided by the interaction between the respiratory system, which allows the enter of oxygen into the body and gets rid of the carbon dioxide, and the circulatory system, which acts transporting carbon dioxide and oxygen to and from the lungs, respectively.
The surface available for the gaseous exchange is enlarged by the pulmonary alveoli. The alveoli are the terminal aerial spaces of the respiratory system and the structures where the exchange between the air and blood is produced. Each alveolus is surrounded by a net of capillaries, where oxygen is freed from the hemoglobin and moves into the cells by diffusion. Carbon dioxide, diffuses out of the cells into the capillaries, where most of it dissolves in the plasma of the blood.
An element found in groups 3-12 of the periodic table is classified as a[n]
Answer:
Transition Metals
Explanation:
Hope this helped :)
balance this chemical equation pleaseee
The half-life of carbon-14 is 5,730 years. Dating organic material by looking for C-14 can't be accurately done after 50,000 years. Suppose a fossilized tree branch originally contained 4.30 grams of C-14. How much C-14 would be left after 50,000 years?
Answer:
0.010g of C-14 would be later after 50,000 years
Explanation:
The kinetics of radioactive decay follows the equation:
Ln (N / N₀) = -kt
Where N could be taken as mass after time t,
N₀ initial mass = 4.30g;
k is rate constant = ln 2 / t(1/2)
= ln 2 / 5730years = 1.2097x10⁻⁴ years ⁻¹
Replacing:
Ln (N / 4.30g) = -1.2097x10⁻⁴ years ⁻¹ * 50000 years
N / 4.30 = 2.36x10⁻³
N =
0.010g of C-14 would be later after 50,000 yearsfirst to answer correctly gets brainleist
In sexual reproduction, how many genes does an offspring receive for each trait ♀️
Answer:
Each parent's half of the genes acquired by the offspring. They have two of each chromosome and hence two alleles of each gene, and one acquired from each parent.
GUYS I NEED THIS ASAP
why is the moisture of cirrus clouds mostly in the solid state
Answer:
Wind is the horizontal movement of air, transporting energy transferred from the earth's surface as sensible and latent heat. Sensible heat is transferred by the processes of conduction and convection. Conduction transfers energy within a substance, and convection transfers energy through the vertical movement of the heated substance. Latent heat is the transfer of energy by transforming the substance itself. As you recall, water has the ability to exist as liquid, gas or solid. The transformation from liquid to gas is called evaporation; the reverse process, from gas to liquid, is called condensation; from liquid to solid is known as solidification (freezing); and from solid to liquid, fusion (melting). Water can also be transformed directly from solid to gas (sublimation), or the reverse, through a process called deposition. We will see these various processes in the formation of clouds.
Explanation:
if I did not give answer then i hope i at least helped!
Hydrofluoric acid (HF) can be prepared according to the following equation:
CaF2 + H2SO4 2 HF + CaSO4.
How many grams of HF can be prepared from 75.0 g of H2SO4 and 63.0 g of CaF2?
In the above problem, which reactant is limiting and which is in excess?
Given the balanced equation:
( Reaction type : double replacement)
CaF2 + H2SO4 → CaSO4 + 2HFI
We can determine the number of grams prepared from the quantity of 75.0 H2SO4, and 63.0g of CaF2 by converting these grams to moles per substance.
This can be done by evaluating the atomic mass of each element of the substance, and totaling it to find the molecular mass.
For H2SO4 or hydrogen sulfate it's molecular mass is the sum of the quantity of atomic mass per element. H×2 + S×1 + O×4 = ≈1.01×2 + ≈32.06×1 + ≈16×4 = 2.02 + 32.06 + 64 = 98.08 u (Dalton's or Da) or g / mol.
For CaF2 or calcium fluoride, it's molecular mass adds 1 atomic mass of calcium and 2 atomic masses of fluoride due to the number of atoms.
Ca×1 + F×2 = ≈40.07×1 + ≈19×2 = 40.08 + 38 = 78.07 u (Da or Dalton's) or g / mol.
The limiting reactant in the given balanced reaction is sulphuric acid. The mass of HF produced from 75 g of H₂SO₄ is 30 g.
What is limiting reactant?The limiting reactant in a species is the reactant which is fewer in amount and thus determine the yield of the product.
In the given reaction, one mole of calcium fluoride reacts with one mole of sulphuric acid to give two moles of HF. The molar mass of calcium fluoride CaF₂ is 78 g/mol the weight taken here is 63 g. Thus number of moles is 63/78 = 0.87 moles.
The molar mass of sulphuric acid H₂SO₄ is 100g/mol. The weight taken here is 75 g and thus, number of moles is 75/100 = 0.75 moles. One mole of calcium fluoride need one mole of H₂SO₄ . Thus 0.87 neede 0.87 moles of H₂SO₄ . But here we have only 0.75. Thus it is the limiting reactant.
As per the reaction, one mole or 100 g of H₂SO₄ produce 2 moles or 40 g of HF (molar mass = 20 g/mol). Thus mass of HF produced from 75 g is calculated as follows:
mass of HF = (75 × 40)/100
= 30 g.
Hence, mass of HF produced in this reaction is 30 g.
To find more about limiting reactant, refer the link below:
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A sector of a circle has an area of 132m². if the angle of the sector is 105,°,calculate the radius of the circle
Calculate the frequency of a wave that is 4.3 x 10^-11 m the speed of light 5 points
is 3x10^8 m/s *
1 Add file
PLEASE HELP
Which of the following is the FIRST step in solving the SI conversion problems?
PLEASE HELP, WILL MARK BRAINLIEST!!!
A) Fill in the "railroad tracks".
B) Write the relationship between the 2 units.
C) Review the SI prefixes.
D) Move decimals around to ensure the answer is in scientific notation.
Answer:
A
Explanation:
Answer:
It is A!
Explanation:
Heat being transferred from a hot pan to our food while cooking is an example of... *
conduction
convection
radiation
transpiration
A.conduction i hope it helps
Answer:
conduction
Explanation:
A 20.0g sample of metal with a specific heat of 5 J/(g°C) raised it's initial temperature to 40.0 when 500J heat was added. What was the initial temperature of the metal?
The initial temperature of the metal = 35 °C
Further explanationHeat can be formulated :
Q = m . c . ΔT
Q = heat, J
c = specific heat, J/g C
ΔT = temperature, °C
m = 20 g
c = 5 J/(g°C)
Q = 500 J
T₁ = 40 C
the initial temperature :
[tex]\tt \Delta t(T_2-T_1)=\dfrac{Q}{m.c}\\\\40-T_1=\dfrac{500}{20.5}\\\\40-T_1=5\\\\T_1=35^oC[/tex]
Q3: Fingers and hands pulling, pushing, pressing, or lifting are all examples of applying a
Is it friction gravity motion or force
Answer:
force
Explanation:
because the force
describe how electricity moves through wires
What happens in a double-replacement reaction?
A. An element replaces an element in another compound.
B. Two reactants combine to form one compound.
C. One compound separates into two or more products.
O D. The elements in two compounds switch places
Answer: D
Explanation: trust
Answer:
Explanation:
D
Liquid Nitrogen’s temperature is minus what degress
Answer:
-320f
Explanation:
Why do clothes stick together when coming out of a dryer? And do the clothes start off as neutral?
here is what came up when i searched it up:
"The attraction between protons and electrons can also make clothes stick together in the dryer. When you dry clothes in the dryer, different fabrics rub together, and electrons from a cotton sock (for instance) may rub off onto a polyester shirt."
Sometimes, clothes can get stuck together after they come out of a dryer because of static electricity.
No, clothes may not start off as neutral. Whether clothes have static charges before going into the dryer depends on different things.
Why do clothes stick together when coming out of a dryer?Static electricity happens when certain things touch and create an uneven amount of electrons. This can cause one material to have a positive charge and the other to have a negative charge. When clothes move and touch each other in a dryer, this rubbing can cause static electricity.
If the clothes are cleaned and dried correctly, they should have no charge or be evenly charged.
Read more about clothes here:
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Write the electron configuration for Br, with 35 protons and 35 electrons.
Answer:
2 8 8 8 8 1
Explanation:
An experiment was conducted to determine the density of a rock sample. The table shows a partial record of the experiment.
Experimental Record
Mass of Rock
86.59
Volume of Water in the Graduated Cylinder 142.5 mL
?
What information should be recorded in the last row of the table?
Answer: the density of the rock
55.91g/ml
Explanation:
The density of the rock after it had being placed in the cylinder of water so the calculation should look like this:
Volume of water substract the mass of the rock:
And that is 142.5 ml - 86.59g =
Answer 55.91 g/ml
So the density of the rock is 55.91g/ml
A mixture of the gases neon and krypton is in a 2.00 L container with a pressure of 1.60 atm. The partial pressure of the neon is 0.40 atm. What is the partial pressure of the krypton?
Answer:
P(Kr) = 1.2 atm
Explanation:
According to Dalton law of partial pressure,
The total pressure inside container is equal to the sum of partial pressures of individual gases present in container.
Mathematical expression:
P(total) = P₁ + P₂ + P₃+ ............+Pₙ
Now we will solve this problem by using this law
Total pressure = 1.60 atm
Partial pressure of neon = 0.40 atm
Partial pressure of krypton = ?
Solution:
P(total) = P(Ne)+ P(Kr)
1.60 atm = 0.40 atm +P(Kr)
P(Kr) = 1.60 atm - 0.40 atm
P(Kr) = 1.2 atm
The partial pressure of Krypton in the mixture has been 1.2 atm.
Partial pressure can be defined as the pressure exerted by a single gas in the solution.
According to Dalton’s law of partial pressure, the total pressure of the gas has been the summation of the partial pressure of each gas present in the mixture.
Total pressure = Partial pressure of A + Partial pressure of B + Partial pressure of C……
The given mixture has been consisted of neon and krypton. The total pressure of the mixture has been:
Total pressure = Partial pressure of Ne + Partial pressure of Kr
The total pressure = 1.60 atm.
The partial pressure of Ne = 0.40 atm.
Substituting the values:
1.60 atm = 0.40 atm + Partial pressure of Kr
Partial pressure of Kr = 1.60 - 0.40 atm
Partial pressure of Kr = 1.2 atm.
The partial pressure of Krypton in the mixture has been 1.2 atm.
For more information about the partial pressure, refer to the link:
https://brainly.com/question/8408970
What is the volume of 89.6 moles of gas at STP *