(C) 320 g
Explanation:
A = A02^(-t/hl)
where hl = half-life
A0 = original amount
A = present amount
t = elapsed time = 5 half-lives
10g = A02^(-5) = A0/32
A0 = 32×(10 g) = 320 g
pls help it's about density
A dry, solid rock conducts electricity better than a long, meta wire.
True
False
Answer:
false
Explanation:
metal such as copper, silver, etc conducts heat and electricity. an object such as a rock, plastic, paper does NOT conduct heat.
How many liters of hydrogen are obtained from the reaction of 4.00 g sodium with excess water, at STP?
Answer:
V = 1.95 L.
Explanation:
Hell there!
In this case, according to the following reaction between sodium metal and water:
[tex]2Na+2H_2O\rightarrow 2NaOH+H_2[/tex]
We can realize that the moles of hydrogen can be calculated by using the initial mass of sodium, its atomic mass (23.0 g/mol) and the 2:1 mole ratio of sodium to hydrogen to obtain:
[tex]4.00gNa*\frac{1molNa}{23.0gNa} *\frac{1molH_2}{2molNa}=0.0870molH_2[/tex]
Finally, we calculate the volume of hydrogen by using the ideal gas equation whereas the pressure is 1 atm and the temperature 273.15 K according to the STP conditions:
[tex]PV=nRT\\\\V=\frac{nRT}{P}\\\\V=\frac{0.0870mol*0.08206\frac{atm*L}{mol*K}*273.15 K}{1 atm}\\\\V=1.95L[/tex]
Regards!
Helium only has two valence electrons and is a stable atom. How is this possible when atoms
need 8 valence electron to become stable?
Answer:
Explanation:
Helium (He) is similar in that it, too, only has room for two electrons in its only valence shell. Hydrogen and helium have only one electron shell. The first shell has only one s orbital and no p orbital, so it holds only two electrons. Therefore, these elements are most stable when they have two electrons.
A 1.85 kg textbook is sitting on a bookshelf 2.23 m above the floor. How much potential energy does it have?
Answer:
[tex]\boxed {\boxed {\sf 40.4299 \ Joules}}[/tex]
Explanation:
Potential energy is energy due to position. It is the product of mass, height, and acceleration due to gravity.
[tex]PE= m \times g \times h[/tex]
The mass of the textbook is 1.85 kilograms. Assuming this is on Earth, the acceleration due to gravity is 9.8 meters per square second. The height is 2.23 meters.
m= 1.85 kg g= 9.8 m/s²h= 2.23 mSubstitute the values into the formula.
[tex]PE = 1.85 \ kg \times 9.8 \ m/s^2 \times 2.23 \ m[/tex]
Multiply the first 2 numbers together.
[tex]PE=18.13 \ kg*m/s^2 *2.23 \ m[/tex]
Multiply again.
[tex]PE= 40.4299 \ kg*m^2/s^2[/tex]
1 kilogram square meter per square second (1 kg*m²/s²) is equal to 1 Joules (J) Our answer of 40.4299 kg*m²/s² is equal to 40.4299 J[tex]PE= 40.4299 \ J[/tex]
The textbook has 40.4299 Joules of potential energy.
Plz Answer Fam & Con Chemistry (8TH GRADE)
Answer:
claw techniques
Explanation:
because it is
Which is the correct Lewis dot structure of NH2?
H-N-H
H-N-H
A.
B.
N-H-H
H-N-H
C.
D.
-H-N-H
E.
ОА А
ов. В
C C
OD D
ОЕ Е
Answer:
D
Explanation:
(reporting links) giving brainly
Which of the following are indicators of a healthy water source?
A.high nitrates, high pH, and low temperatures
B.low temperature, high dissolved oxygen, and neutral pH
C.low pH, high nitrates, and low dissolved oxygen
D.high turbidity, high dissolved oxygen, and high temperature
Answer:
B.
Explanation:
B. low temperature, high dissolved oxygen, and neutral pH
Hope this Helps.
What can you say about the forces between the particles of these gases)
Answer:
Gas – In a gas, particles are in continual straight-line motion. The kinetic energy of the molecule is greater than the attractive force between them, thus they are much farther apart and move freely of each other. In most cases, there are essentially no attractive forces between particles.
Explanation:hopes this helps:)
Write the molecular formula of poly(glycine)
Answer:
C2H5NO2
Explanation:
Glycine | C2H5NO2 - PubChem.
weight of glycine= 75.07 g/mol
Describe how nucleic acid basis pair up
The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T) C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)
The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The A-T pair forms two hydrogen bonds. The C-G pair forms three. The hydrogen bonding between complementary bases holds the two strands of DNA together.
Water and oil are "immiscible", meaning they do not mix but stay
separated when combined in a glass. What is the best explanation for this?
1.both are polar molecules
2.both are nonpolar molecules
3.water is a polar molecule and oil is a nonpolar molecule
4.water and oil are both compounds
Answer:
Good luck man
Explanation:
Good luck man
Why are infants and children often more susceptible to the effects of toxic substances than adult? (Explain)
From what I know personally from learning about this type of subject in the past is that children are more susceptible to the effects of toxic substances more than adults are, certain scientific data specifically indicate that children actually are for all intents and purposes more basically susceptible to toxic exposure than adults because they for the most part have proportionally definitely more intake of food contaminants, basically active developmental processes, basically multiple exposure pathways and really susceptible kind of socio-behavioral activities in a particularly major way.
Describe the law of conservation of mass in your own words *DO IT IN YOUR OWN WORDS PLEASE*
Answer:
Chemical reactions and physical transformations do not create or destroy mass in an isolated system, according to the law of conservation of mass. The mass of the products in a chemical reaction must equal the mass of the reactants, according to the conservation of mass law. The law of conservation of mass can be used to solve for unknown masses, such as how much gas is consumed or produced during a reaction.
What can be different between the products and reactants in a balanced chemical equation?
Answer:Reactants are starting materials and are written on the left-hand side of the equation. Products are the end-result of the reaction and are written on the right-hand side of the equation.
Explanation:
The reactants in a balanced chemical reaction are the starting material which reacts together to give the products in by the regrouping of atoms in the reactants.
What is a balanced chemical equation?The balanced chemical equation of a reaction represents the perfect stoichiometry of each reactants and products with their states of matter in brackets.
In a balanced reaction, the number of each element in the reactant side must be equal to their number in the product side. The number of each elements and groups in a reaction can be balanced by multiplying with suitable integers.
The atoms in the reactants are regrouping to form the products. Thus, the identity of the new products is entirely different form that of reactants in the reaction.
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Which statement most accurately describes a chemical equation?
a. in a chemical reaction, the mass of the energy change must be equal to the energy used
b. in a chemical reaction, the mass of the products must equal the mass of the reactants
c. in a chemical reaction, the mass of each product must be the same
d. in a chemical reaction, the combined mass of the container the substances is always equal
Answer: A
Explanation:
Which statement is true in comparison to a weak acid, a strong acid
has a larger ph than weak acids
is more concentrated than we gases
strong acids produced less H plus ions is mostly H plus ions in solution
Answer: Strong acid vs weak acid
Strong acids and strong bases refer to species that completely dissociate to form ions in solution.
Explanation: By contrast, weak acids and bases ionize only partially, and the ionization reaction is reversible. Thus, weak acid and base solutions contain multiple charged and uncharged species in dynamic equilibrium.
Collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction.
Answer: The statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.
Explanation:
Activation energy is the minimum amount of energy required to initiate a chemical reaction.
So, when activation energy for a reaction is lower then molecules with lower energy can also participate in the reaction. As a result, more number of collisions will take place due to which an increase in the rate of reaction will takes place.
When activation energy for a reaction is larger then molecules with higher energy will not be able to participate in the reaction. As a result, less number of collisions will take place due to which a decrease in rate of reaction will occur.
Therefore, we can conclude that the statement collisions only result in a reaction if the particles collide with a certain maximum energy called the activation energy of the reaction, is false.
Answer:
true
Explanation:
particularly must collide with energy equal to or greater the
How many units long is the circumference of a circle with diameter of 18 units?
Answer:
56.52 units
Explanation:
hope that helps :)
How many days does it take the moon to orbit the Earth once.
Answer:
27.3 days
Explanation:
I really have no explanation lol.
Answer:
Hope thia helps
Explanation:
it takes 27.3 days!!!
what type of reaction is Pb + CuCl2 ---> PbCl2 + Cu
The above reaction is a Single displacement reaction , in which lead (Pb) being more reactive displaces Copper (Cu) from its compound [tex](\mathrm{CuCl_2})[/tex] and forms Lead Chloride [tex](\mathrm{PbCl_2})[/tex].
[tex] \boxed{\mathrm{Pb + CuCl_2 \rightarrow PbCl_2 + Cu}}[/tex]
_____________________________
[tex]\mathrm{ \#TeeNForeveR} \: ☃[/tex]
ILL MARK BRAINLIEST :)
Describe the law of conservation of mass in your own words *DO IT IN YOUR OWN WORDS PLEASE*
Explanation:
According to the law of conservation of mass, mass can neither be created nor destroyed but it can simply be transformed from one form to another.
For example, [tex]Na^{+} + Cl^{-} \rightarrow NaCl[/tex]
Mass of Na = 23 g/mol
Mass of Cl = 35.5 g/mol
Sum of mass of reactants = mass of Na + mass of Cl
= 23 + 35.5 g/mol
= 58.5 g/mol
Mass of product formed is as follows.
Mass of NaCl = mass of Na + mass of Cl
= (23 g/mol + 35.5) g/mol
= 58.5 g/mol
As mass reacted is equal to the amount of mass formed. This shows that mass is conserved.
As a result, law of conservation of mass is obeyed.
Select the correct answer.
A compound has an empirical formula of C2H5. What is true about this empirical formula?
ОА It models the structure of the compound.
ОВ. It shows the ratio of elements in the compound.
Ос. . It gives the mass of each atom in the compound.
OD. It indicates the number of atoms in the compound.
O E. It describes only this one compound.
Answer: OB
Explanation:
The empirical formula of an element is the simplest formula of an element which shows the ratios of atoms of the each element present in a molecule of a compound .
Iodine-131 half life 8.040 how long will it take for a 40 gram sample of iodine-131 to decay to 0.75 grams
Answer:
See explanation below
Explanation:
To get this, we need to apply the general expression for half life decay:
N = N₀e(-λt) (1)
Where:
N and N₀ would be the final and innitial quantities, in this case, masses.
t: time required to decay
λ: factor related to half life
From the above expression we need λ and t. To get λ we use the following expression:
λ = t₁₂/ln2 (2)
And we have the value of half life, so, replacing we have:
λ = 8.04 / ln2 = 11.6
Now, we can replace in (1) and then, solve for t:
0.75 = 40 exp(-11.6t)
0.75 / 40 = exp(-11.6t)
ln(0.01875) = -11.6t
-3.9766 = -11.6t
t = -3.9766 / -11.6
t = 0.34 daysA sample of helium has a volume of 3.49 L at 741 mmHg. What would be the volume if the pressure
were changed to 760 mmHg at the same temperature?
show work
P1: 741 mmHg
V1: 3.49 L P1 x V1 / P2= (741 mmHg) (3.49 L) / 760 mmHg = 3.40 L
P2: 760 mmHg
V2: ? L
an organism that lives in or on another organism and causes harm to is a
A. host
B. parasite
C. prey
D. producer
the answer is B. Parasite.
Which of the following are HETEROGENEOUS mixtures from this list (check all that apply).
A. Air
B. Sweet Tea
C. Trail mix
D. Soil
E. Beach sand
F. Water
C
ot 헤
C.
Show that the results of these dulys
Calculate the oxidation state of Manganese in the following
i. KMnO4 ii. Mno4-
i) KMnO4
lets calculate using x method
1+x+ 4(-2) = 0
1+x-8 =0
x= 7
ii)MnO4‐
x+4(-2) = -1
x-8 = -1
x = 7
PLEASE HELP QUICKLY!!
I know it's not A or B; I just can't figure it out between C and D.
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What will most likely happen when a component is added to a reaction system at equilibrium?
A. The system will be unaffected by stress.
B. The addition of a catalyst will change the equilibrium.
C. The equilibrium position will shift away from what was added to lower its concentration.
D. The equilibrium position will shift away from what was added to increase its concentration.
Answer:
c: The equilibrium position will shift away from what was added to lower its concentration.
Explanation:
Answer: C. The equilibrium position will shift away from what was added to lower its concentration.
Explanation:
If we have a system that is already in equilibrium, the addition of an extra amount of one of the reactants or one of the products throws the system out of equilibrium. Either the forward or the reverse reaction will then occur to restore equilibrium conditions.
How is a radioactive element different from a stable element?
Radioactive elements are the elements into which an atom is very unstable or highly reactive because it is having more energy in its nucleus. stable elements are those who have stable and there shell are properly filled with electrons.
What are radioactive elements and stable elements?Most radioactive chemical elements have one or more radioactive isotopes on the other hand some chemical elements only have one type of radioactive isotopes.
A radioactive element has an unstable nucleus that emits particles in the form of alpha, beta, or gamma radiation and stable element have stable nucleus with no effect of any radiation or energy due to fully filled orbitals.
Bombarding of these radiations has to be done in the nucleus of the element after this the desired element will become a radioactive element. And there is no effect of these rays on stable elements beacuse they are unreactive to this.
The ray of alpha beta and gamma consists of some charges within them and they are radioactive radiations harmful to human eyes.
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