Answer:
.
Explanation:
A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much
potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
A. 4.20
B. 8.40 g
c. 12.6 g
D. 16.8 g
E. 25.2 g
Answer:
The correct answer is b
Explanation:
Answer:
Correct Answer is (B)
Explanation:
Got it right on plato Chemistry Post test
Hope I helped you out :)
Which of the following properties would a substance that has metallic bonding
normally have?
I. thermal conductivity
II. electrical conductivity
III. malleability
IV. ductility
Answer:
I, II, III,IV
Explanation:
Metals are known to possess metallic bonds. In a metallic bond, electro-positive metals loose electrons which form a cloud of electrons which exerts an attractive force on the positive metallic ions. This attractive force holds the metal atoms together in the crystal lattice.
The physical properties of metals include;
I. thermal conductivity
II. electrical conductivity
III. malleability
IV. ductility
Hence, substances that exhibit properties I-IV are metals and have metallic bonds.
The following properties which a substance that has metallic bonding
normally have include
thermal conductivityelectrical conductivitymalleabilityductilityMetals are elements which have metallic bonding which is always strong as
it helps to form a lattice.
Metals are good conductors of heat and electric current , they can also be
bent in to different shapes . This means it has all the properties listed above.
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How many liters of water are needed to dissolve 75.0 grams of NaOH to prepare a 1.00-M solution?
Answer:
About 500
Explanation:
Bc i used my calc
NEED HELP FAST!!!! 20 POINTS!
Answer:
it would be C!!
Explanation:
balancing skeleton equation can someone help me with this
When any chemical equation is not balanced then that is known as skeletal chemical equation. We need to balance it because as we know that mass can neither be created nor be distroyed and also the number of atoms on the reactant side should always be equal to the compounds on the product side .
*BRAINLIEST BRAINLIEST
Which wavelength would have the highest energy?
670 nanometers
1.3x10^-10 meters
5.3x10^-8 meters
1.5x10^-3 meters
Answer:
THE 3 third one
Explanation:
Gizmo Student Exploration: Periodic Trends
Does anyone have the answer key?
Answer:
No
Explanation:
I dont at least but you may be lucky
The atomic number of Arsenic (As) is 33 and the average atomic mass is 74.92 amu. A neutral arsenic atom will have protons
Given :
The atomic number of Arsenic (As) is 33.
The average atomic mass is 74.92 amu.
To Find :
A neutral arsenic atom will have protons.
Solution :
We know, atomic mass is the sum of number of protons and neutrons.
Also, atomic number is the number of protons present in an atom.
Therefore, a neutral arsenic atom will have 33 protons.
Lithium
Which statement about lithium describes what makes lithium very reactive?
F.
The number of neutrons in the nucleus.
G
The number of electrons in the first energy level.
H.
The number of protons in the nucleus.
J.
The number of electrons in the last energy level.
Answer:f
Explanation:
Among the groups of elements listed below, which have the same number of electrons in their outermost energy levels? C, K, Ca, Rb, Sr
Na,Mg,AI,S
Li,B,C,F
F,CI,Br,I
Answer:
i believe its d
Explanation:
Answer:
I checked and I too think its D
how many moles of oxygen molecules can be produced from 6 moles of lead oxide
Answer:
Moles of oxygen molecules produced = 3 mol
Explanation:
Given data:
Moles of oxygen molecules produced = ?
Number of moles of lead oxide decomposed = 6 mol
Solution:
Chemical equation:
2PbO₂ → 2PbO + O₂
Now we will compare the moles of oxygen and lead oxide.
PbO₂ : O₂
2 : 1
6 : 1/2×6 =3 mol
three moles of oxygen molecules are produced.
find the odd one out of --retina,cochlea,ciliary muscles,cornea
Answer:
cochlea
Explanation:
Under which conditions does a real gas behave most like an ideal gas? A. At low temperatures and high pressures B. At low temperatures and low pressures C. At high temperatures and high pressures D. At high temperatures and low pressures
Answer: D. At high temperatures and low pressures
Explanation:
At low temperature and high pressure, the kinetic energy of gas molecules is negligible and molecules will have negligible forces of attraction. So real gases will behave least like an ideal gas under such conditions.
At high temperature and low pressure, energy due to intermolecular forces becomes less important in comparison to the kinetic energy of particles. The size of molecules also become less significant than the empty space between the gas molecules. So real gases behave in a similar manner to ideal gases at high temperature and low pressure.
how many double bonds are in the lewis structure for carbon dioxide, CO2 ?
Answer:
the answer is two double bonds
Hi can anyone help Mehh ! :D
Answer: Renewable becuase the trees can be cut and then replanted.
Explanation:
Non-Renewable resources are resources that cannot be replenished easily through natural process. These are the sources which are used in wise manner so that they do not get depleted. For example: coal, petroleum etc.
Renewable resources are resources that can be replenished overtime through natural process.These are the sources which never depletes completely. For example: bio mass energy, solar energy etc.
As trees can be replenished easily through natural process but it takes a long time for it to occur, it is a renewable source.
. Which of the following statements about solutions is false?
a. All solutions are mixtures.
b. All solutions are homogeneous.
c. All solutions contain two or more compounds.
d. All solutions contain at least two substances.
Answer:
B
Explanation:
The statement false about solution has been that all solutions are mixtures. Thus, option A is correct.
The solution can be defined as the dissolution of two or more substances. Thus, all solutions are been considered as dissolution of the solute and solvent molecules.
The solution has generally been the homogenous mixture as there has been the complete dissolution of the substances. However, the mixture can be defined as the combination and not the complete dissolution of the substances.
Thus, all solutions have not been considered as mixtures. Thus, option A is correct.
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Question 1
1 pts
What part of our planet protects the planet and traps gases inside of our planet?
O hydrosphere
O Earth surface
O atmosphere
core
Uranium-232 has a half-life of 68.8 years. After 344.0 years, how much uranium-232 will remain from a 375.0-g sample?
Uranium-232 will remain 11.72 g
Further explanationThe atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually radioactive elements have an unstable atomic nucleus.
The main particles are emitted by radioactive elements so that they generally decay are alpha (α), beta (β) and gamma (γ) particles
General formulas used in decay:
[tex]\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{T/t\frac{1}{2} }}}[/tex]
T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
t 1/2 = half-life = 68.8 years
T = duration of decay = 344 years
No= initial sample = 375 g
Uranium-232 remain :
[tex]\tt Nt=375.\dfrac{1}{2}^{344/68.8}\\\\Nt=375.\dfrac{1}{2}^5\\\\Nt=11.72~g[/tex]
HELP!!! WILL MARK BRAINLIEST!!!
Which of the following metals is paramagnetic?
Question 5 options:
A)
Calcium
B)
Magnesium
C)
Sodium
D)
Beryllium
Answer:
A , B, C
Explanation: D is a Diamagnetic
The metals that are paramagnetic are Calcium, Magnesium, and Sodium. The correct options are A, B, and C.
What is paramagnetism?A weak magnetic field supplied externally can weakly attract some materials, which then create internal magnetic fields that are directed in the same direction as the applied magnetic field. This phenomenon is known as paramagnetism.
Despite not having an unpaired electron, the metal magnesium exhibits paramagnetic behavior. Sodium is also paramagnetic.
Atoms that have their electrons coupled are said to be diamagnetic, whereas those that don't are said to be paramagnetic. However, despite having no free electrons, calcium is said to be paramagnetic.
Thus, the correct options are A, Calcium, B, Magnesium, and C. Sodium.
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what should we use in soap making process:-
a) potassium hydroxide
b) sodium hydroxide (lye)
Explain why it should be used
Sodium hydroxide, with the formula NaOH, is usually used in products as a pH adjuster. It's also used in soap-making to turn fats and oils into soap. You can find sodium hydroxide (also called caustic soda or lye) in its pure form in the cleaning aisle, since it's also really handy for clearing up clogged drains.
Many of the lunar craters are due to volcanic eruptions true or false
Answer:
false
Explanation:
Craters on the Moon are caused by asteroids and meteorites colliding with the lunar surface. The Moon's surface is covered with thousands of craters. ... It also has very little geologic activity (like volcanoes) or weathering (from wind or rain) so craters remain intact from billions of years.
What is the energy of a photon that emits a light of frequency 7.21 x 1014 Hz? A. 4.78 x 10-19 J B. 2.76 x 10-19 C. 1.0910-19 J D. 4.16 x 10-19 J
Answer:
E = 4.78×10^−19 J
Explanation:
The chemical equation for the energy of a photon is given by:
E =hν , where h is the Planck constant and ν is the frequency.
E =hν = 6.626×10^−34 Js × 7.21×10^ 14
s−1 = 4.78 × 10^−19 J
Answer:
A. 4.78 x 10-19 J
Explanation:
A P E X
Which of these statements accurately describes monomers?
Monomers are macromolecules.
Monomers contain double bonds.
Monomers are made of repeating units.
Monomers contain bonds between metals.
Answer:
Monomers contain bonds between metals
Answer:
B: Monomers contain double bonds
Explanation:
I got it right on Edge
GIVING BRAINLIEST!
Please define the following in your own words:
law of conservation of matter
Answer:
No new matter can be created, and no matter can be destroyed. Matter can only change in state or chemical composition. The amount of mass before the change will equal the amount after the change.
Explanation:
Sieving is a technique used to separate mixtures containing solid particles of
(a) small sizes
(b) large sizes
(c) the same sizes
(d) different sizes
it can be be be be be ebe be e e
Elements in the same column of the periodic table of the elements all
Answer:
Each column is called a group. The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements.
Explanation:
Answer:
the elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons.
~+lil more info +~
The vertical columns (groups) of the periodic table are arranged such that all its elements have the same number of valence electrons. All elements within a certain group thus share similar properties.
The diagram below shows the energy conversions of the Krebs cycle, which is part of cellular respiration. The U-shaped
arrows that show changes for NAD, FAD, and ADP molecules represent energy conversions. From each glucose
molecule, two acetyl-CoA molecules are made for the Krebs cycle.
NADH
NAD+
FADH2
FAD
Acetyl-CoA
СС
COA
COA
Citric Acid
4-carbon
compound
CCCC
co&Co
ADP
ATP
CO2
NADH
NAD+
5-carbon
compound
CCCCC
NAD+
NADH
CO.
How many energy conversions occur when both acetyl-CoA molecules go through the Kerbs cycle
A 5
B 6
C 10
D 12
Answer:
b
Explanation:
How many grams are there in 4.30 x 10²⁶ molecules of H₂SO₄?
Mass of H₂SO₄ : 69,972 g
Further explanationA mole is a number of particles(atoms, molecules, ions) in a substance
This refers to the atomic total of the 12 gr C-12 which is equal to 6.02.10²³, so 1 mole = 6.02.10²³ particles
Can be formulated :
N = n x No
N = number of particles
n = mol
No = 6.02.10²³ = Avogadro's number
moles of H₂SO₄ :
[tex]\tt mol=\dfrac{N}{No}\\\\mol=\dfrac{4.3\times 10^{26}}{6.02\times 10^{23}}\\\\mol=7.14\times 10^2[/tex]
mass H₂SO₄ (MW=98 g/mol) :
[tex]\tt mass=mol\times MW\\\\mass=7.14.10^2\times 98\\\\mass=69,972~g[/tex]
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A bottle of hydrogen peroxide that eventually turns into a bottle of water and oxygen gas is an example of a
