I need help, plz help me with this problem
Answer:
It's b
Explanation:
I had the same exact question
Zn-71 has a half life of 2.4 minutes. If one had 100g at the beginning, how many grams would be left after 12 minutes?
3.125g
Explanation
2.4 minutes = 1 half life
so 12 minutes = 5 half lives (12/2.4)
100g/2 = 50g (1 half life)
50g/2 = 25g (2 half lives)
25g/2 = 12.5g (3 half lives)
12.5g/2 = 6.25g (4 half lives)
6.25g/2 = 3.125g (5 half lives)
What part of the periodic table does the neutrons tell us about the element?
Answer:
The neutrons tell us if it is an isotope or not, they also hold the atom together.
Explanation:
A force of 5N accelerates an object. The object mass is 50 g. What is the acceleration of an object?
Answer:
100 m/ s²
Explanation:
Newton's Second Law of Motion:
[tex] \boxed{ \mathsf{force = mass \times acceleration}}[/tex]
___________________
In the question:
Force applied = 5 N mass of the object experiencing force = 50 gNote that the quantities here must be in their SI units.
SI unit of Force is Newton(N).
SI unit of mass is kilogram(kg)
Force is already in it's SI unit, while mass isn't.
Converting mass from grams to kilograms:
1000 g = 1 kg
=> 1 g = 1/ 1000 kg
=> 50 g = 50/ 1000 kg
= 1/ 20 kg
___________________
Calculating acceleration:
[tex] \mathsf{5 = \frac{1}{20} \times acceleration }[/tex]
multiplying both sides by 20:
[tex] \implies \mathsf{5 \times 20= (\frac{1}{20} \times 20)\times acceleration }[/tex]
20 on the RHS gets canceled, for it's present on the numerator as well as the denominator.
[tex] \implies \mathsf{100= acceleration }[/tex]
So, here, we got acceleration = 100 m/s².
Since, the other quantities used in the formula are in their SI units, acceleration must be in it's SI unit as well.
The SI unit of acceleration is m/s²
___________________
Answer:
[tex] \boxed{ \mathsf{100 \:m/s^2= acceleration }}[/tex]
2) Nitrogen gas will react with hydrogen gas to produce ammonia, NH3, How many
moles of hydrogen gas are required to produce 0,86 moles of NH3?
Answer:
12 grams of hydrogen gas
and 56 grams of nitrogen gas
The molar mass of ammonia is 17 g/mol.
68 grams of ammonia corresponds to
17g/mol
68g
=4moles
4 moles of ammonia will be obtained from
2
4×1
=2 moles of nitrogen and
2
4×3
=6 moles of hydrogen.
The molar masses of nitrogen and hydrogen are 28 g/mol and 2 g/mol respectively.
2 moles of nitrogen corresponds to 2×28=56 grams.
6 moles of hydrogen corresponds to 6×2=12 grams.
Analyze the reaction of solid magnesium and water. Which pair of reactants and products in the table below represent the correct balanced equation for the reaction?
Answer:
3 is correct answer I think
Explanation:
Labor unions arose in the nineteenth century as increasing numbers of Americans took jobs in factories, mines, and mills in the growing industrial economy.
The Knights of Labor, founded in 1869, was the first major labor organization in the United States. The Knights organized unskilled and skilled workers, campaigned for an eight hour workday, and aspired to form a cooperative society in which laborers owned the industries in which they worked.
The Knights’ membership collapsed following the 1886 Haymarket Square riot in Chicago. By 1886 the American Federation of Labor (AFL), an alliance of skilled workers’ trade unions, was growing.
Help
what is isotopes
Figure 2
Describe how a dog grows. Describe their mode of reproduction
Explanation:
Although all puppies are officially considered adult dogs once they reach one year old, puppies continue to grow in height and size while their bones are still developing, which takes anywhere from 6 to 24 months. Their skeletal growth is what determines how tall they will become as adults.
A little help here please
Answer:
Prokaryotic Cells:
- Bacteria
- Unicellular Organisms
- DNA as genetic material
- Ribosomes
- Do not have membrane bound organelles
- Always contain cell wall
Eukaryotic Cells:
- Contains organelles
- Have membrane bound organelles
- Unicellular Organism
- DNA as genetic material
- Ribosomes
- Have loose strand of DNA
- Has nucleus
- Multicellular Organism
- Plant cell
- Animal cell
Explanation:
I have separated them and made the common characteristics in bold. I cannot guarantee that it is correct, these are my educated estimates.
how do you find a mole (i need an example) i hate chem pls help
Answer:
I'm pretty sure its just the mass of the sample divided by the molar mass
for example if I had like 7g of carbon and wanted to find the moles, I would divide the mass I have (7g) by the molar mass (the atomic mass value on your periodic table, in this case for carbon it would be 14g)
moles = [tex]\frac{mass}{molarmass} = \frac{7}{14} = 0.5\ moles[/tex]
Hope this helped
the speed of sound is greater through a solid than through a gas because the molecules in a solid are
A. still
B. vibrating
C. farther apart
D. closer together
A 0.03 mol sample of NH4NO3 (s) is placed in a 1 L evacuated flask, which is then sealed and heated. The NH4NO3 (s) decomposes completely according to the balanced equation above. The total pressure in the flask measured at 400 K is closest to which of the following? (The value of the gas constant, R, is 0.082 L atm mol-1 K-1.)
a. 3 atm
b. 1 atm
c. 0.5 atm
d. 0.1 atm
e. 0.03 atm
The total pressure in the flask measured at 400 K is 1 atm
The correct answer to the question is Option B. 1 atm
From the question given above, the following data were obtained:
Number of mole (n) = 0.03 mole Volume (V) = 1 L Temperature (T) = 400 KGas constant (R) = 0.082 atm.L/Kmol Pressure (P) =?Using the ideal gas equation, we can obtain the pressure in the flask as follow:
PV = nRT
P × 1 = 0.03 × 0.082 × 400
P = 1 atmTherefore, the total pressure in the flask measured at 400 K is 1 atm
Learn more on ideal gas equation: https://brainly.com/question/4147359
Answer: a: 3 atm
Explanation:
0.03 mol NH4NO3 decomposes into 0.09 mol of gas total, thus we multiply 0.09 by 0.082 and 400K to get our answer of about 3 atm.
What does it mean to optimize a solution ?
How are solutions optimize
Question
What does it mean to optimize a solution?
To find out best possible solution for a given problem within the given constraint is generally termed as optimization
How are solution optimize ?
To solve an optimization problem, begin by drawing a picture and introducing variables. Find an equation relating the variables. Find a function of one variable to describe the quantity that is to be minimized or maximized. Look for critical points to locate local extrema.
the ____ changes when electrons are gained or lost.
Answer: Matter changes when electrons are gained or lost.
Explanation:
The charge on an atom changes when electrons are gained or lost during chemical changes.
What is an atom?An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether it is solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged particles and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral species and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
Learn more about atom,here:
https://brainly.com/question/13654549
#SPJ6
Am I right? Yes or no?
Answer:
yes because it is right and because
Answer: The answer is true.
Explanation: You picked 1 5 6 9 which is correct, I think you picked that but I can't see
Reactions cannot occur without a certain minimum amount of energy. What is this minimum amount of energy called?
the activation energy
the activated complex
the kinetic energy of reactants
the potential energy of products
Which animal is found in the desert?
monkeys
parrots
buffalo
meerkats
Answer:
meerkats
Explanation:
why must a ph meter be calibrated by using a solution with a known ph value
Answer:
A pH calibration is the process of adjusting your pH meter by measuring solutions of a known pH value. This is because the characteristics of your electrode will change over time and this needs to be compensated for. A calibration does this by matching your pH meter to the current characteristics of your pH sensor.
Explanation:
One of the products when aqueous Na, CO, reacts with aqueous
Sn(NO3), is
O a. Sn(CO3)2
O b. CNO3
O c. NaSn.
O d. NaNO3
Answer:
NaNO3
balanced equation - Na2CO3 + Sn(NO3)2 → 2NaNO3 + Sn(CO3)
Which of the following is a binary compound?
4. Pb + FeSO4 → PbSO4 + Fe
what type of reaction?
Oxidation- Reduction reaction
Is this a male cat or female?
Explanation:
Lift the kitten's tail. The opening just under the tail is the anus. Below the anus is the genital opening which is round in males and is a vertical slit in females. In kittens of similar size, the distance between the anus and the genital opening is greater in the male than the female.
TW: use of inapropate words*
Answer:
not enough information to tell
Explanation:
One way you can tell this difference is the distance between the cat's genitals (organs seen on the outside of the body) and the anus. A male will have a much greater distance between the genitals and anus than females, 1/2 inch apart on a male kitten and over 1 inch apart on a male adult cat. However, if the two are almost adjacent on a kitten or less than 1/2 inch apart on an adult, it’s a female.
When you take a hot shower, the
a
shower curtain sometimes moves
into the shower towards you. Why
does this happen?
With hot water comes hot steam, it fills the shower area with steam which raises the air temperature and the air then rises out of the shower
How many particles would be found in a 12.7 g sample of ammonium carbonate? Show workkk
Answer:
7.8286×10²¹ particles
Explanation:
give me brainlist please
`Carbon Dioxide and Water are the _______ in a chemical reaction. 2. Reactants are also called the starting _______ in a chemical reaction.: Reactants are also called the starting _______ in a chemical reaction. 3. This type of energy comes from the sun: a This type of energy comes from the sun 4. You get this type of energy from food: b You get this type of energy from food 5. The process by which plants use the sun to produce glucose and oxygen.: The process by which plants use the sun to produce glucose and oxygen. 6. The products of photosynthesis: The products of photosynthesis 7. The location of photosynthesis in plant cells: The location of photosynthesis in plant cells 8. Another name for glucose is: Another name for glucose is 9. Energy is provided by this cell organelle during cellular respiration: Energy is provided by this cell organelle during cellular respiration 10. The largest source of energy on earth comes from the: d The largest source of energy on earth comes from the Column B a.Chloroplast b.Ingredients c.Reactants d.Sun e.Radiant energy f.Sugar g.Chemical energy h.Glucose and Oxygen i.Mitochondria j.Photosynthesis
What is the total amount of work done when Danny lifted 25 pounds of weight over 5 meters and applying 30- Newtons of Force?
Answer:
Definition and Mathematics of Work
Calculating the Amount of Work Done by Forces
Potential Energy
Kinetic Energy
Mechanical Energy
can you help me with this
Answer:
I think it is A
Explanation:
if I am wrong I am so so so sorry
but i'm pretty sure I am right.
please let me know if I am right :)
how do the prefixes of the –saccharide words relate to the structure of the sugar?
Answer:
The prefixes tell you how many of each there are.
Explanation:
So for this example, mono would mean there is one sugar, di meaning 2 sugars and so on. Hope this helped!
Here is a table:
mono- 1 hexa-6
di-2 hepta- 7
tri- 3 octo- 8
tetra- 4 nona- 9
penta - 5 deca- 10
I NEED MORE HELP ASAPP
Answer:
1) Gas
2) Higher
3) Increases
4) Higher
Explanation:
Why is the molecule not an example of a cis stereoisomer
Answer:
Because in order to have cis or trans configuration both carbon of alkene need to have a hydrogen
