Carbon-14, which is present in all living tissue, radioactively decays via a first-order process. A one-gram sample of wood taken from a living tree gives a rate for carbon-14 decay of 13.6 counts per minute. If the half-life for carbon-14 is 5720 years, how old is a wood sample that gives a rate for carbon-14 decay of 7.9 counts per minute?
A. 5.3 x 102 yr.B. 7.6 x 102 yr.C. 1.1 x 103 yr.D. 9.5 x 103 yr.
The question is incorrect, the correct question is;
Carbon-14, which is present in all living tissue, radioactively decays via a first-order process. A one-gram sample of wood taken from a living tree gives a rate for carbon-14 decay of 13.6 counts per minute. If the half-life for carbon-14 is 5720 years, how old is a wood sample that gives a rate for carbon-14 decay of 11.9 counts per minute?
Answer:
C. 1.1 x 103 yr
Explanation:
A = count rate of the wood sample
Ao= count rate of a living tissue
t1/2= half life of C-14
t = time taken
From;
0.693/t1/2 = 2.303/t log Ao/A
0.693/5720 = 2.303/t log (13.6/11.9)
1.2 * 10^-4 = 2.303/t * 0.05799
1.2 * 10^-4 = 0.1336/t
t = 0.1336/1.2 * 10^-4
t = 1.1 x 103 yr
What is the name of the "invisible force" that holds you to Earth's surface
Answer:
Gravity
Explanation:
Answer: gravity
Explanation: gravity has is an “invisible force” that holds matter down instead of floating off into space.
Nick needs 3.5 moles of sodium fluoride (NaF) for a solution he is mixing in the lab. How many grams of NaF does Nick need to measure out?
Answer:
147 g
Explanation:
The number of moles of a substance is the ratio of the mass of the substance and the molar mass of that substance. Mathematically,
mole = mass of substance/molar mass
In this case, Nick needs 3.5 moles of NaF, the molar mass of NaF is calculated as:
23 + 19 = 42 g/mol (Note: Na = 23, F = 19)
Hence,
mass of 3.5 mole NaF = mole x molar mass
= 3.5 x 42 = 147 g.
Hence, Nick would need to measure out 147 g NaF using a suitable weighing balance.
A motorist discovers that her auto tire measures 29.2 psi rather than the recommended 35 psi. If the tire’s volume is assumed constant at 11.6 L and the temperature is 45F at the filling station, how many moles of air will the motorist need to add to bring the tire to 35 psi? (assume 1.00 atm = 14.7 psi)
Answer:
0.20 moles
Explanation:
The pressure is proportional to the quantity of gas at a given temperature and volume. So, the quantity needs to be increased by a factor of ...
(35 psi)/(29.2 psi) = 175/146 ≈ 1.19863
The fractional increase required is ...
1.19863 -1 = 0.19863
__
The quantity of air currently in the tire is ...
1 mol·519.67°R/(atm·23.6442 L) × (29.2/14.7 atm) × (11.6 L) / (45+459.67)°R
= 1.0035 mol
so we need to add ...
(fraction to add) × (current quantity) = amount to add
0.19863 × 1.0035 mol = 0.1993 mol = amount to add
About 0.20 moles of air must be added to the tire to bring the pressure up.
How many known elements have atoms, in their ground-state, with valence electrons whose quantum numbers are n = 5 and l = 1?a. 36..
b. 37.
c. 6.
d. 8.
Answer:
c. 6.
Explanation:
Looking at the description given in the question, the elements involved must belong to the p- block of the periodic table and must be in period 5. They also must possess valence electrons in the 5p- orbital.
Now if we look at the p- block of period 5, the following elements satisfy these requirements; Sr, In, Sn, Sb, Te and I.
Hence there are six of such elements.
The chemical elements that have atoms, in their ground-state, with valence electrons whose quantum numbers are n = 5 and l = 1 are: C. 6.
What is a valence electron?A valence electron can be defined as the number of electrons that is present in the outermost shell of an atom.
In Chemistry, valence electrons are primarily used to determine whether an atom or group of chemical elements that are found on the periodic table can bond with others.
Based on electronic configuration, quantum numbers of n = 5 and l = 1 simply represents a 6p orbital and there a total of six (6) chemical elements with this orbital, and these include;
ThalliumLeadRadonAstatinePoloniumBismuthRead more on valence electrons here: https://brainly.com/question/16554158
The sun is the biggest source of visible_
energy caused by the movement of waves of
_____
Answer:
the sun is the biggest source of visible (solar?) energy caused by the movement of waves of (electromagnetic?)
Not confident sry :(
Explanation:
In a chemical formula or a chemical equation, what is the small number after the element symbol?
Answer:
It's called a subscript.
Explanation:
Subscripts tell you how many atoms of an element are in a compound.
True or False
ATP energy is used to move muscles and build protein in your body
using the ideal gas law, PV=nRT, where R=0.0821 L atm/mol K, calculate the volume in liters of oxygen produced by the catalytic decomposition of 25.5 g potassium chlorate according to the following reaction. The oxygen is collected at 2.22 atm and 25.44 C. express your answer to the correct number of significant figures.
2KClO3(s) ---> 2KCl(s) + 3O2(g)
Answer:
V = 2.32 Liters
Explanation:
PV = nRT => V = nRT/P
n = 25.8g/122g/mole = 0.21 mole
R = 0.08206 L·atm/mol·K
T = 25.44°C + 273 = 298.44K
P = 2.22 atm (given in problem)
V = (0.21mol)(0.08206 L·atm/mol·K)(298.44K)/(2.22atm) = 2.32 Liters at 25.44°C & 2.22atm
What element has the noble gas configuration [Ne]3s23p??
Answer:
Sulfur
Explanation:
The first ten electrons of the sodium atom are the inner-shell electrons and the configuration of just those ten electrons is exactly the same as the configuration of the element neon (Z = 10).
...
Noble Gas Configurations.
Element Name Sulfur
Symbol S
Atomic Number 16
Noble Gas Electron Configuration [Ne]3s23p4
How do atoms form chemical bonds
Answer:
Atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. A chemical bond is a force of attraction between atoms or ions. Bonds form when atoms share or transfer valence electrons. In a covalent bond, two atoms share one or more electrons.
Answer the in under 30 minutes and I will give brainliest
After which event in Indonesia did one of the worst tsunamis form?
a hurricane
a volcanic eruption
a landslide
an earthquake
Answer: I believe the answer is an earthquake.
Explanation: Sorry If I am wrong!
Answer:
earthquake
Explanation:
I took the k12 test
need help asap........................................
Answer:
its a
Explanation:
beacause the movement goes forward
At room temperature, one of the molecules is a gas and one is a liquid. Identify which structure is a gas and which is a liquid.
what is meant by the term quantitative?
A) number measurement
B) words & explanation
Answer:
a) number measurement
Explanation:
relating to, measuring, or measured by the quantity of something rather than its quality.
Answer:
number and measurement
Explanation:
Quantitative is an adjective that simply means something that can be measured. For example, we can count the number of sheep on a farm or measure the gallons of milk produced by a cow.
how many valence electrons in an oxygen atom?
Answer:
6 valence electrons
Explanation:
Valence electrons are the electrons in the outermost shell, or energy level, of an atom. For example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell.
At which part of a river would you have the best luck growing food?
A. Bend
B. Delta
C. Alluvial fan
D. Source
Answer:
B. Delta
Explanation:
What is the volume of 100 g neon at STP?
Answer:
Well
STP
specifies 100⋅kPa,and 273.15⋅K...
Explanation:
And so we solve for n
moles of gas
in the Ideal Gas equation, and of course we have to fish out an appropriate gas constant...
n=PVRT=100⋅kPa×10⋅L8.314⋅L⋅kPa⋅K−1⋅mol−1×273.15⋅K
=0.440⋅mol
And thus a mass of 0.440⋅mol×20.18⋅g⋅mol−1...approx. 9⋅g...
Explanation:
Is temperature beginning to rise a physical or chemical change?
Answer:
If temperature increases, as it does in most reactions, a chemical change is likely to be occurring. This is different from the physical temperature change. During a physical temperature change, one substance, such as water is being heated.
Explanation:
Answer:
the least of these are to get some good deals for a circle for your business
Explanation:
GG have been in which I was not have a chance of the square and it
what's element on the periodic table has the symbol w
Answer:
W is tungsten on the periodic table
Which products of photosynthesis does your body break down to be used for cellular respiration?
Answer:
Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide, which is used in photosynthesis. While water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.
hope this helps!
How many atoms of hydrogen in the product side of the balanced equation?
Fe + H2O ---> FeO + H2
A) 2
B) 3
C)6
Answer:
i think the answer should be a
How do substances and mixtures diifer
The composition of one is always the same, and the composition of the other varies
One contains only one type of atom, and the other contains two or more
One is always homogeneous, and the other is always heterogeneous
One contains one type of molecule, and the other contains two types
it for 100 points please give it correctly.
Answer:
hello hope this helps :)
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
Question in picture plsss help
Answer:
2nd answer is correct. Hope it helped you!
why are there different types of matter.
Answer:
solid ; liquid and gas........
if you have 4 moles of n2 and 6 moles of h2, how much would be produced?
Answer:
8 i think
Explanation:
To evaluate R. the volume of a gas measured in the temperature of the gas is measured in
while
Answer:It is necessary to use Kelvin for the temperature and it is conventional to use the SI unit of liters for the volume.
Explanation:
However, pressure is commonly measured in one of three units: kPa, atm, or mmHg. Therefore, can have three different values.
Answer: liters; Kelvin
Explanation:
What’s a good summary for pseudoscience?
Answer:
Beliefs or practices that are regarded as "scientific" and "factual" but have not been proven nor are they backed by science.
Explanation:
Example: Astrology
bonds. Carbon dioxide has a. Ionic b. Covalent c. Nonpolar covalent d. Polar covalent
Answer:
B
Explanation:
Covalent bond.
Your aunt is sipping on iced tea and fanning herself during a hot South Carolina summer day. You tell her that there is enough energy in one drop of her iced tea to run the air conditioner for the rest of her life if the energy could be extracted with 100% efficiency. Your aunt asks you to explain. Use the concepts you learned in this unit to explain the relationship between forces, energy, and matter.
Answer:
Isn't this like having enough energy to supply the world for centuries with just 1% of the sea's force?
Explanation:
I guess it's because the amount of energy in it can supply energy.