Answer:
true
Explanation:
hydrogen and carbon make hydrocarbons
High temperatures inside Earth form
melted rock.
fossils.
soil.
minerals.
Answer:
minerals
Explanation:
Hope this helps
When doing medical research with human subjects, which four limitations are unavoidable?
Answer:
Answer
The limitations are-
1. Privacy of the individuals involved in the research process.
2. Physical and psychological risks should be minimized
3. The subjects should be chosen equitably
4. Only reasonable exposure to risks is admissible.
Explanation
The privacy of the individuals involved in the research must be taken into consideration. This will ensure safety of patient data and information. The risk of physical and physiological well being of the person must be taken into consideration in such a research. In addition to that, the subject must be made to understand every procedure and the risks involved before testing. Moreover, only minimal exposure to risks is allowed and must have been previously tested in animals to avoid deaths.
Scientific Notation!!!!!
#9 b) PLEASE HELP!!!
Explanation:
9) a) (9.84×10³)/(6.12×4.27×10³+⁷) = 9.84×10³/6.12×4.27×10¹⁰ = 9.84×10³-¹⁰/6.12×4.27
= 0.376×10^-7.
b) (4.36×10⁸×1.82×10³)/(0.0856×4.7×10⁶)
= (7.9352×10⁸+³)/(0.40232×10⁶)
= 19.72×10⁸+³-⁶ = 19.72×10⁵
hope this helps you.
Determine the number of moles in a sample of 2.82g B
Answer:
0.123 mol
Explanation:
1 mol Na/22.99g na=0.123 mol
Answer:
[tex]\boxed {\boxed {\sf 0.261 \ mol \ B}}[/tex]
Explanation:
We are asked to find the number of moles in a sample of 2.82 grams of boron.
We convert grams to moles using the molar mass or the mass of 1 mole of a substance. These values are found on the Periodic Table. They are equivalent to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up the molar mass of boron (B).
B: 10.81 g/molConvert using dimensional analysis. Set up a conversion factor using the molar mass.
[tex]\frac {10.81 \ g \ B}{ 1 \ mol \ B}[/tex]
We are converting 2.82 grams of boron to moles, so we multiply by this value.
[tex]2.82 \ g \ B *\frac {10.81 \ g \ B}{ 1 \ mol \ B}[/tex]
Flip the ratio so the units of grams of boron cancel.
[tex]2.82 \ g \ B *\frac { 1 \ mol \ B}{10.81 \ g \ B}[/tex]
[tex]2.82*\frac { 1 \ mol \ B}{10.81}[/tex]
[tex]\frac {2.82}{10.81} \ mol \ B[/tex]
[tex]0.2608695652 \ mol \ B[/tex]
The original value of grams has 3 significant figures, so our answer must have the same. For the number we found, this is the thousandth place. The 8 in the ten-thousandth place tells us to round the 0 up to a 1.
[tex]0.261 \ mol \ B[/tex]
There are approximately 0.261 moles of boron (B)in 2.82 grams of boron.
John Dalton thought that atoms
1. Cannot be broken down further
2. Have no mass
3. Contain molecules
4. Are all composed of carbon
Answer:
cannot be broken down further
why does exercising causes the change in our body ( breathing/heart rate)
Answer:
Explanation:
The biggest change in the body caused by regular exercise is to muscle tissue. ... At the cellular level, exercise triggers the release of substances that dilate the blood vessels in the muscle, letting in more oxygen, says Prof Bradford. These are short-term effects, but deeper changes come with regular exercise.
Exercising causes changes in our body because we're working our muscles so there's more going on with us compared to when we're just laying down. We need more oxygen to go to our muscles so we breathe harder and more rapidly. Our heart also beats faster because it needs to pump more blood to the muscles that are being worked.
What is the mass % of acetone in a 1.85 M solution of acetone (MM = 58.08 g/mol) in water? The density of the solution is 0.971 g/mL.
A 1.85 M acetone solution (MM = 58.08 g/mol) with a density of 0.971 g/mL has a mass percent of acetone of 11.0%.
What is the mass percent?It refers to the mass of solute in 100 grams of solution.
Let's suppose we have 1 L of the solution.
Step 1: Calculate the mass of solute (acetone).We have a 1.85 M solution of acetone (MM = 58.08 g/mol). We will calculate the mass of acetone using the following expression for molarity.
M = mass acetone / MM acetone × liters solution
mass acetone = M × MM acetone × liters solution
mass acetone = 1.85 mol/L × 58.08 g/mol × 1 L = 107 g
Step 2: Calculate the mass of the solution.We have 1 L (1000 mL) of the solution with a density of 0.971 g/mL.
1000 mL × 0.971 g/mL = 971 g
Step 3: Calculate the mass percent of acetone.%acetone = (107 g/971 g) × 100% = 11.0 %
A 1.85 M acetone solution (MM = 58.08 g/mol) with a density of 0.971 g/mL has a mass percent of acetone of 11.0%.
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Aluminium sulphate is organic or inorganic compound
Answer:
Aluminium sulphate is an inorganic compound.
Describe how you could show by adding aqueous sodium hydroxide and aqueous ammonia that a solution contained zinc ions.
Answer:
Learning Task 3. Solving word problems involving multiplication of deci-
the
A cstep in solving word problems. Do these in your notebook. ),
1. A clerk is paid P 45.25 per hour for 40 hours a week, 1.50 times the
regular rate for overtime and double the rate for a holiday. How much
holiday?
2. fofkmputer programmer earns a regular hourly rate of P50.00. If he
worked 42.75 hours in a week, how much did he earn?
3. Arthur earns P1350.00 a day. He sets aside 0.10 of this for savings.
How much does he save in a month?
4. Mr. Fernandez has a monthly pay of P 5,450. The tax deducted from
year?
5. Dianne works 2.5 hours a day from Monday to Friday and 3.75 hours
his a
on Saturday. If he is paid P25.00 per hour, how much does he earn in
a
week?
Explanation:
Learning Task 3. Solving word problems involving multiplication of deci-
the
A cstep in solving word problems. Do these in your notebook. ),
1. A clerk is paid P 45.25 per hour for 40 hours a week, 1.50 times the
regular rate for overtime and double the rate for a holiday. How much
holiday?
2. fofkmputer programmer earns a regular hourly rate of P50.00. If he
worked 42.75 hours in a week, how much did he earn?
3. Arthur earns P1350.00 a day. He sets aside 0.10 of this for savings.
How much does he save in a month?
4. Mr. Fernandez has a monthly pay of P 5,450. The tax deducted from
year?
5. Dianne works 2.5 hours a day from Monday to Friday and 3.75 hours
his a
on Saturday. If he is paid P25.00 per hour, how much does he earn in
a
week?
Which substances will make a salt when combined?
Vinegar and soda
Soda and wine
Detergent and ammonia
Fertilizer and vinegar
Answer:
vinegar and soda
Explanation:
Mixing baking soda (sodium bicarbonate) and vinegar (acetic acid) causes a chemical reaction that produces a salt (sodium acetate) and water, as well as carbon dioxide gas.
Answer:
Fertilizer and vinegar
Explanation:
Fertilizer is a base, and vinegar is an acid. Salt is made when you combine a base and an acid. Plus, I got a 100% on the test and this was my answer.
what is the percent by volume of a solution formed by mixing 25ml of isopropanol with 45ml water
Answer:
I assume that you mix the 25 mL alcohol with 45 mL water.
The answer depends on a big IF : IF the volumes are additive. Very often volumes of liquids are not additive
Total volume = 70 mL
isopropyl alcohol %(v/v) = 25mL/ 70 mL * 100 % = 35.7% v/v
The answer should have only 2 significant digits: 36%v/v
Explanation:
Hope it helps
The percent by volume of a solution formed by mixing 25 ml of isopropanol with 45 ml of water is 35.71% which is rounded off to 36%.
What is meant by percent by volume of a solution?Percent volume is defined as the concentration of a particular solute which is measured in terms of volume present in a solution. The volume of the solution is present in the denominator which indicates the total volume of all components .
It is expressed as,
percent volume= volume of solute/volume of solution×100
It is used for solutions which are made by mixing two components . It is one of the ways of expressing concentrations of mixture with a dimensionless quantity.
Percent volume of the given solution is calculated by substituting the given values in the formula like, 25/70×100=35.71%
Thus, the percent by volume concentration of the solution is 35.71%≈36%.
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A solution is prepared by diluting 6.0 mL of a 7.6 x 10-4 g/mL solution to a total volume
of 10.0 mL. Calculate the concentration of the dilute solution.
Answer:
4.56 X 10^ -4 g/mL
Explanation:
A solution is prepared by diluting 6.0 mL of a 7.6 x 10-4 g/mL solution to a total volume of 10.0 mL. Calculate the concentration of the dilute solution.
(7.6 X10^-4 gm/m L) x( 6.0 m L ) = 45.6 X 10^-4 g
this is dissolved )in 10 m L=45.6 X 10^-4 g/ 10
4.56 X 10^ -4 g/mL
check
6/10 =0.6
4.56/7.6 = o.,6
Calculate the number of days after the explosion for a sample of iodine-131 to go from 100%
iodine-131 to less than 1% iodine-131. Complete chart.
It will take 56 days to go from 100% iodine-131 to less than 1% iodine-131.
From the table, we can see that the half life of iodine-131 is 8 days. We can see that it takes 8 days to have 50% of iodine-131
After 16 days, we will have 25 % of iodine-131
After 24 days, we will have 12.5 % of iodine-131
After 32 days, we will have 6.25% of iodine-131
After 40 days, we will have 3.125% of iodine-131
After 48 days, we will have 1.5625% of iodine-131
After 56 days, we will have 0.78125% of iodine-131
After 56 days, the percentage of iodine-131 drops to less than 1%.
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What would be the product when combustion reaction occurs in a small tightly-closed container?
Answer:
Incomplete combustion produces carbon monoxide along with some carbon dioxide. Water is always produced during combustion. If the fuel is sulfur containing, carbon disulfide will result as well.
Have a happy day! <3Miss Hawaii
Explanation:
Which characteristic do valence electrons indicate about reactions between atoms? (1 point)
o electronegativity difference
o absolute electronegativity
o bond type
o bond number
The characteristic of reactions that depends on valence electrons is the bond type.
In chemistry, a chemical bond could be;
IonicCovalentThe type of bond formed depends on the number of valence electrons present. When there are few valence electrons on an atom, it mostly forms ionic bonds.
When there are more electrons on an atoms, it mostly forms covalent bonds and the electrons between the atoms are shared.
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Answer:
D: bond number
Materials Visible Uniform Not Visible Non- Uniform State of Matter 1. Sugar and water 2. Oil and water 3. Vinegar and water 4. Salt and pepper 5. leaf and water
Answer:
1. Uniform, non visible
2. Visible, non uniform
3. Uniform, non visible
4. Visible, non uniform
5. Visible, non uniform
Explanation:
A heterogeneous mixture is simply any mixture that is not uniform in composition — it's a non-uniform mixture of smaller constituent parts. By contrast, a mixture that is uniform in composition is a homogenous mixture
visible state of matter is when you can easily difference two components of a mixture
non visible is when the state of the matter in the substance is not visible to the eye, it can't be differentiated
What did you include in your response? Check all that
apply.
o Organisms eat food to obtain carbohydrates, lipids,
and proteins, which are found in food.
Organisms use these molecules for energy and
growth.
Answer:
WHAT DID YOU INCLUDE IN YOUR RESPONSE
Please help me with all ASAP I’ll mark brainly
Answer:
Explanation:
1.c
2.j
3.h
4.b
5.f
6.d
7.a
8.i
9.e
10.g
PLEASE EXPLAIN I KNOW THE ANSWER I NEED AN EXPLAINATION
The potential energy as a function of internuclear distance for three diatomic molecules, X2, Y2, and Z2, is shown in the graph above. Based on the data in the graph, which of the following
From the graph shown, Y2 = N2, X2 = O2, Z2 = H2.
When atoms of elements are at a large distance from each other, the potential energy of the system is high. However, as the atoms approach each other, the potential energy of the system decreases steadily. The closer the atoms come to each other, the lower the potential energy. This implies that potential energy is proportional to bond length.
Since N2 has a shorter bond length and higher energy, Y2 must be N2. The bond energy of hydrogen is small hence H2 must be X2. The bond energy of a double bond is intermediate between that of a single and triple bond hence Z2 must be O2.
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6. What is the atomic mass of Hafnium if out of every 200 atoms, 10 have mass 176.00 g/mol, 38 have mass
177.00 g/mol, 54 have mass 178.00 g/mol, 28 have mass 179.00 g/mol, and 70 have mass 180.00 g/mol?
Answer:
ttyhjj
Explanation:
Alka-Seltzer is pure NaHCO3
True or false?
Answer:
falso
Explanation:
How many atoms of Xe does 7.84 moles of Xe contain?
can someone help me please ... god will bless u if u help...it is very urgent... i only have 1hr to answer this question
Answer:
iuiwusiwuiqihihiuwusbhwubduywbduywbudb me no esspanlo
Explanation:
niuniniuniuniun
What is the sum of the atomic numbers of each element present in the reactants of the given formula?
2 NH3 + H2SO4 → (NH4)2SO4
Answer:
25
Explanation: They all add up to 25 Atoms
The atomic number of nitrogen is 7 and that of oxygen is 8. Atomic number of hydrogen is one and the atomic number of sulphur is 16. Then, the sum of atomic numbers of each element present in the reactants of the given formula is 32.
What is atomic number ?The atomic number of an atom is the number of electrons in its neutral state. This number is equal to the number of protons also. The modern periodic table classify all elements based on their atomic numbers.
The sum of number of protons and neutrons of an element is called its mass number. For the given formula, the elements present are H, O, N and S.
atomic number of H = 1
atomic numebr of N = 7
atomic number of O =8
atomic number of S = 16.
Then ,sum of atomic number s= 1 + 7 + 8 + 16 = 32.
Therefore, the sum of the atomic numbers of each element present in the reactants of the given formula is 32.
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helpppppppppppppppppppppppppp
Answer:
The answer is B(the path water takes from Earth to the clouds and back again)
A chemical reaction takes place in a closed system. The mass of the reactants before the reaction was grams. What must the mass of the products of the reaction be, according to the law of conservation of mass?
A. 35 grams B. 30 grams C. 70 grams D. 25 grams
Answer:
D. 25 grams
Explanation:
I think that's what the answer is
An atom contains three protons, two neutrons, and one electron. What is the charge of the nucleus?
A: 3+
B: 5+
C: 2+
D: 0
Answer:
A.3+
Explanation:
️️️️️️️️️️️️️️
Can anyone tell me why I got this question wrong? I have no clue.
Answer:
what queastiion
Explanation:
Answer:
what is the question
Explanation:
...
Calculate the approximate number of sodium ions in 2.52 g of sodium sulphate,
Na2SO4.
Explanation:
Please send me the answer of this question
help please ill do anything really!!!!!!!
Answer:
The first one is air the second is decreases the third is water the fourth is gas and the last is liquid.
Explanation:
Hope it helps.
