Answer:
this one is hard
Explanation:
but it's iron because the sodium so yea there u go.
How abundant is Polonium in the earth's crust?
Even in pitchblende, polonium is exceedingly rare: 1,000 tons of ore must be treated to yield 40 milligrams of polonium. It has a one-part-in-ten-thousandth-thousandth-thousandth-thousandth-thousandth-thousandth It is found in nature as a byproduct of the radioactive decay of uranium, thorium, and actinium.
Atomic Number: 210
Consider a 0.241 M aqueous solution of sodium hydroxide, NaOH.
A. How many grams of NaOH are dissolved in 24.43 mL?
B. How many individual hydroxide ions (OH-) are found in 24.43 mL?
C. How many moles of sulfuric acid, H2SO4, are neutralized by 24.43 mL of 0.241 M NaOH(aq)?
Answer:
a. 0.2355052g
Explanation:
a)
1000ml of NaOH contain 0.241moles
24.43ml of NaOH contain (24.43*0.241)/1000 moles
= 0.00588763moles
Relative Molecular Mass of NaOH
= 1*23 + 1*16 + 1*1
= 40
1mole of NaOH weighs 40g
0.00588763moles weigh (0.00588763*40) g
= 0.2355052g
B)
NaOH -> Na+ + -OH
1 mole of NaOH dissociates to form 1 mole of -OH ions
1 mole of a substance contains 6.02*10^23 particles(atoms)
= 0.00588763 * 6.02 *10^23
= ______ions
How many grams of N2 are required to react with 4.2 moles of Mg in the following process?
3 Mg + N2 → Mg3N2? (Mg = 24.3 g/mol, N = 14.0 g/mol)
Answer:
x = 0.45*28/3 = 4.2 g
Explanation:
showing work
N2 = 28 g/mole
3Mg + N2 → Mg3N2
3moles .. 28 g
0.45 moles .. x
x = 0.45*28/3 = 4.2 g (answer)
Solutions which can conduct electricity must contain:
atoms
minerals
molecules
ions
Answer
Ions
Explanation
Would you expect a Boron (B) atom with atomic mass = 9.999 to be stable?
The balance of forces allows to find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 uma is unstable because the repulsive force increases.The stability of atomic nuclei depends on the balance the force is electrostatic repulsion between the protons and the strong interaction of attraction.
One way to achieve this balance is to increase the separation of the protons with uncharged particles between them, the neutral ones, the strong interaction is of the same magnitude for protons and neutrons, therefore the repulsion is decreased and the strong attraction interaction is maintained. .
In the case of Boron, which has 5 protons, the stable structures have more atomistic 10 and 11 una, which is why it has 5 and 6 neutrons each. Therefore each proton has a neutrons next to it and in the other case a proton at the end has two neutrons, this causes the distance between the protons to increase, decreasing the electrostatic repulsion.
It indicates that we have a Boron nucleus of mass 9.999. The number of protons must remain fixed, therefore there are only 4 neutrons.
Consequently, some of the protons does not have a neutron next to it and can approach the other proton, therefore the electrostatic repulsion increases and the stability of the atom decreases.
In conclusion, using the balance of Forces we can find the result for the question if the isotope of boron 9.99 una is stable:
The boron isotope of mass 9.99 amu is unstable because the repulsive force increases.Learn more about nuclear stability here: https://brainly.com/question/897383
Sulfuric acid reacts with sodium carbonate to form water, a salt, and a gas. Write the formulas for the salt and other compound that are formed in the reaction.
Answer:
H2So4 + Na2Co3 -> H20 + Na2So4 + CO2
The chemical formulas for the salt and other compound that are formed in the reaction are Na₂SO₄,H₂O and CO₂.
What is chemical formula?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
There are four types of chemical formula:
1)empirical formula
2) structural formula
3)condensed formula
4)molecular formula
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A sample of CO2 gas at 100 degrees Celsius has a volume of 250 mL at 760 mm Hg. How many moles of CO2 are present
There are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
HOW TO CALCULATE NUMBER OF MOLES:
The number of moles of a sample of gas can be calculated using the following formula:
PV = nRT
Where;
P = pressure of gas (atm)V = volume (L)n = number of moles (mol)R = gas law constant (0.0821 Latm/molK)T = temperature (K)According to this question;
P = 760mmHg = 1 atmT = 100°C = 100 + 273 = 373KV = 250mL = 0.250Ln = ?1 × 0.250 = n × 0.0821 × 373
0.250 = 30.62n
n = 0.250 ÷ 30.62
n = 8.16 × 10-³mol
Therefore, there are 8.16 × 10-³ moles of CO2 gas at 100°C with a volume of 250 mL at 760 mm Hg.
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Define atomic numbers and mass numbers
Answer:
1). Atoms of each element contain a characteristic number of protons. In fact, the number of protons determines what atom we are looking at (e.g., all atoms with six protons are carbon atoms); the number of protons in an atom is called the atomic number.
2) In contrast, the number of neutrons for a given element can vary. Forms of the same atom that differ only in their number of neutrons are called isotopes.
3) Together, the number of protons and the number of neutrons determine an element’s mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.
Which type of molecule is propanol?
A. Alcohol
B. Aldehyde
C. Ketone
D. Amine
Answer:
A
Explanation:
Alcohol is a type of molecule in propanol. Hence, option A is correct.
What is propanol?Propanol molecular formula is C₃H₇OH.
C₃H₇OH contains -OH functional group which belongs to alcohol.
Hence, option A is correct.
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A substance has a molar heat of combustion of -810.4 kj/mol. when 0.285 mol of the substance is burned in a calorimeter containing 8.60 kg of water, the increase in water temperature is:
Answer:
6.42 °C
Explanation:
Q = mcΔT
Q = energy gain/release (J)
m = mass (kg)
c = specific heat capacity (J/°C/kg)
ΔT = change in temperature (°C)
Qs = n(ΔH°c)
Qs = energy gained/released from substance (kJ)
n = moles (mol)
ΔH°c = molar heat of combustion (kJ/mol)
m = 8.60
n = 0.285
ΔH°c = -810.4
c (of water) = 4184
Qs = 0.285(-810.4)
Qs = -230.964 (or -230964 J)
Q = 230964
230964 = (8.60)(4184)ΔT
230964 = 35982.4(ΔT)
ΔT = 6.4188... °C → 6.42 °C
Which type of energy uses the photoelectric effect?
Biomass
Solar
Geothermal
Wind
Answer:
My lovely people the answer is SOLAR
Explanation:
i just know
The type of energy that uses the photoelectric effect is solar energy. Therefore, the correct option is option B.
When light strikes a material surface, the photoelectric effect takes place, which results in the emission of electrons. Albert Einstein made this intriguing discovery in 1905, and it was essential in the development of quantum physics and our comprehension of the nature of light. The fundamental principle underlying the photoelectric effect is that light is made up of small energy packets known as photons. A photon's energy can be transferred to an electron in a solid or atom when it interacts with those structures. The type of energy that uses the photoelectric effect is solar energy.
Therefore, the correct option is option B.
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What is the empirical formula for C2H4S2?
Answer:
46
Explanation: ihjk
how many sightings of fish in spongebob were there, person who gets it right will get brainliest on god on everything
The model below shows the equation that represents how hydrogen and oxygen combine to form water. In this chemical reaction, the reactants
are hydrogen gas and oxygen gas.
2H2 + O2 + 2H2O
True
False
Answer:
true
Explanation:
because they are balance
What can a scientist use to observe very small things?
1. A good pair of glasses
2. Tools and technology
3. The five senses
4. Sense of touch
Answer:
2
Explanation:
depends on how small but you wouldn't be able to see with good glasses your senses or your touch
Answer:
Tools and Technology ( Microscopes etc)
Explanation:
Glasses are not good enough to see on the molecular and cellular level.
The five senses aren't reliable and can vary between people.
Touch is one of the 5 senses, and touching chemicals isn't good.
A flexible vessel contains 78.00 L of gas at a pressure of 1.50 atm. Under conditions of constant temperature
and moles of gas, what is the pressure of the gas when the volume of the vessel is tripled?
The pressure of the gas when the volume of the vessel is tripled is 0.50 atm.
To find the volume of the gas, we use Boyle's law which states that for a given mass of gas at constant temperature, the pressure is inveresly proportional to its volume. This is stated mathematically as P ∝ 1/V.
So, PV = constant
P₁V₁ = P₂V₂ where P₁ = initial pressure of gas = 1.50 atm, P₂ = final pressure of gas, V₁ = initial volume of gas = 78.00 L and V₂ = final volume of gas = 3V₁ (since the volume of the gas is tripled)
So, making P₂ the subject of the formula, we have
P₂ = P₁V₁/V₂
Substituting the values of the variables into the equation, we have
P₂ = P₁V₁/V₂
P₂ = 1.50 atm × V₁/3V₁
P₂ = 1.50 atm/3
P₂ = 0.50 atm
So, the pressure of the gas when the volume of the vessel is tripled is 0.50 atm.
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NEED HELP ASAP WILL GIVE BRAINLIEST
Answer:
0.2491
Explanation:
1mole of a gas contains 6.02 × 10²³molecules
x moles will contain 3.408 × 10²¹
x = 1 × 3.408 × 10²¹/ 6.02 × 10²³
= 5.66 × 10^-3moles
Mole = mass/ molar mass
mass = Mole × molar mass
= 5.66 × 10^-3 × 44.01
= 249.0966 × 10^-3
= 0.2490966
to 4 decimal places = 0.2491
Industrial chemists have to understand the chemistry of oxides.
For example, silicon dioxide is used in glass making and carbon monoxide is used in the
extraction of iron from iron ore.
(i) Explain how burning carbon in air can lead to the formation of carbon monoxide.
(2)
(ii) Write the balanced equation for the reaction between silicon and oxygen.
(2)
Answer:
carbon monoxide can be formed due to incomplete combustion of carbon due to insufficient oxygen supply
2C+O2___2CO
Si+O2____SiO2
convert 3.79 x 10^24 atoms of sodium to grams
mol = 3.79 × 10^24/6.02 × 10^23 = 6.296 mol
mass = 6.296 × 23 = 144.808 grams
2CH3CHO+O2=> 2CH3COOH
Answer:
2CH3CHO + O2 → 2CH3COOH
How many liters of 0.200 M sodium hydroxide do you need to titrate 0.300 L of a 0.100 M diprotic acid to the equivalence point?
The volume of the sodium hydroxide solution needed for the reaction is 0.3 L
We'll begin by writing the balanced equation for the reaction.
H₂X + 2NaOH → 2H₂O + Na₂X
From the balanced equation above, the following data were obtained:
The mole ratio of the acid, H₂X (nA) = 1The mole ratio of base, NaOH (nB) = 2From the question given above, the following data were obtained:
Molarity of base, NaOH (Mb) = 0.2 M. Volume of acid, H₂X (Va) = 0.3 L. Molarity of acid, H₂X (Ma) = 0.1 M. Volume of base, NaOH (Vb) =?MaVa / MbVb = nA / nB
(0.1 × 0.3) / (0.2 × Vb) = 1/2
0.03 / (0.2 × Vb) = 1/2
Cross multiply
0.03 × 2 = 0.2 × Vb
0.06 = 0.2 × Vb
Divide both side by 0.2
Vb = 0.06 / 0.2
Vb = 0.3 LTherefore, the volume of NaOH needed for the reaction is 0.3 L
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A car goes from 0 to 100m/s in 10s what is that acceleration
Answer:
10m\s
Explanation:
given
initial velocity(u)=0
final velocity (v)=100
acceleration(a)=?
we know,
acceleration = v-u/t
= 100-0\10
= 10 m\s
what is involved fashion of male and female gametes to form a zygote which develops into an embryo
Please help me with this question please just help me with what is this is or synthesis singlereplacement
combustion
decomposition
double replacement
Answer:
1) Combustion
2)Synthesis
3)Single Replacement
4)Decomposition
5)Double Replacement
6)Synthesis
7)Double Replacement
8)Single Replacement
9)Combustion
10)Decomposition
Explanation:
Remeber, decomposisition is breaking things apart, synthesis is building them, cobusion will always make water and CO2 and will always burn O2, single replacemnt will have 1 thing replaced (single) and double replacement will have 2 things replaced (double).
Hope this helps!
is the effect of hot and cold water on acid different?
Answer:
When the acid is mixed with the water, an immediate chemical reaction takes place. The formation of carbon dioxide causes breakdown of the sample into finer particles.
The heat in the Stomach rises up, causing esophageal reflux, chronic sinusitis, headaches, eye disorders and problems with the teeth. Furthermore, ingesting cold water creates moisture or “dampness.” Bacteria, candida, and parasites thrive in damp areas, especially in your stomach and uterus.
Giúp mình 2 câu này với ạ
1, Pha 500ml dung dịch HCl 10% (w/v) từ dung dịch 37% (w/w) d=1.19 g/ml
2, Cách pha như thế nào để nhận được 200g dung dịch HCl 25% (w/w) từ dung dịch HCL 37% (d=1.19 g/ml)
Answer:it is wrong answer
Explanation:estro man
using the formula F=ma, what force is required to accelerate a car weighing 642 kg at 13 m/s2
REALLY NEED HELP RN
HELP ME ?
PLEASE!??
Answer:
8,346 kmxm/s2
Explanation:
this is physics not chem but you just multiply 13 by 642 to get 8,346. also I'm sorry but it's easy
The boiling point of a liquid is tested at 10 different pressures, from 0.5 to 1.4 atmospheres. The results of the tests show that
there is a nearly constant increase in boiling point for each increase in pressure. Which conclusion is reasonable based on this
information? (1 point)
O A boiling point at 1.5 atmospheres could not be predicted with any certainty at all.
O A boiling point at 15 atmospheres could not be predicted with any certainty at all.
O A boiling point at 1.5 atmospheres could be predicted fairly well.
O A boiling point at 15 atmospheres could be predicted fairly well.
Since the increase in boiling point with increasing pressure is fairly constant, then, the boiling point at 1.5 atmospheres could be predicted fairly well.
We say that a substance has reached its boiling point when its pressure equals the atmospheric pressure. Recall that we can be able to make predictions from the results of an experiment.
In this case, we are told that there is a nearly constant increase in boiling point for each increase in pressure. Therefore, it is reasonable to conclude that, a boiling point at 1.5 atmospheres could be predicted fairly well.
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Which of the following expresses the value 300,000,000 in correct scientific notation?
Group of answer choices
3 x 108
0.3 x 10-9
3 x 10-8
0.3 x 109
Answer:
3 x 10^8
Explanation:
In one to two sentences, describe an experiment that would show that intramolecular forces (attractions between atoms within molecules) are stronger than intermolecular forces (attractions between molecules).
Answer:
intra moleculer force is the force which you can't see