Answer:
Explanation:
electronic confirmation=1s^2,2S^2,2P^6,3S^2
atomic no.is 12 therefore :- this is magnesium
Period=3
Block=s-block
Group=II A
Use the equation below to solve the problem that follows.
2H2 (g) + O2 (g) → 2H2O (g)
When David reacts 13.8 grams of hydrogen gas with excess oxygen, 87.0 grams of water are formed. Calculate his percent yield of water.
Percent yield = 70%
Further eplanationPercent yield is the comparison of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Reaction
2H₂ (g) + O₂ (g) → 2H₂O (g)
mass of H₂O (theoretical) :[tex]\tt mass=mol\times MW(mol~ratio~H_2O\div H_2=2\div 2)\\\\mass=(\dfrac{2}{2}\times \dfrac{13.8}{2})\times 18~g/mol\\\\mass=124.2~g[/tex]
percent yield[tex]\tt \%yield=\dfrac{87}{124.2}\times 100\%=\boxed{\bold{70\%}}[/tex]
A student investigated the time taken for amylase to breakdown a 10% starch solution into glucose at
37°C. The student repeated the investigation five times
Figure 11 shows the results
time taken for amylase to produce glucose (s)
Test 4
120
125
110
115
Figure 11
() Calculate the rate of amylase enzyme activity for the 10% starch solution.
Answer:
Phenolphthalein is an indicator. It is pink in alkaline solutions and turns colourless as the pH decreases.
It can be used to measure the activity of the enzyme lipase on the breakdown of lipids.
Samples of milk containing phenolphthalein were incubated with lipase at different temperatures.
The time taken for the phenolphthalein to turn colourless was recorded and used to calculate the rate of enzyme activity.
Figure 10 shows these results.
Picture
(a) (i) Explain why phenolphthalein turns colourless when lipase breaks down the lipids in milk. (2)
(ii) Describe the effect of temperature on the activity of lipase, as shown in Figure 10. (2)
(iii) Explain why the activity of lipase changes above a temperature of 40°C. (2)
(b) A student investigated the time taken for amylase to breakdown a 10% starch solution into glucose at 37°C. The student repeated the investigation five times.
Rain freezes as it hits the ground to form solid water is this a physical change or chemical change?
a. Physical change
b. Chemical change
Can someone help me answer this I will give your brainliest
Answer:
It is Physical Change
Explanation:
Because it is just water turning into another substance of water, nothing chemical is happening.
Boron- 11
Atomic #
Atomic mass
# of protons
# of neutrons
# of electrons
Answer: 5 protons 6 neutrons and 5 electrons. and atomic number is 5.
Hope this helps!
8. Which type of element requires the least amount of energy to remove an electron?
Answer:
nonmetals
Explanation:
Which of the following materials would probably be used as a conductor of electric current in a computer chip?
A rubber
B. glass
c. plastic
D. gold
Answer:
gold is metal which is a very good conductor for electric current and most chips are made out of it.
Answer:
The answer is D. gold
Explanation:
Which of the following are soluble in water: salt, gravel, or pepper
Which best describes the current model of the atom?
O A a central nucleus containing protons with electrons orbiting in specific paths
O B. a solid sphere unique for everything that exists
O c a solid sphere with electrons and protons embedded
O D. a central nucleus containing protons and neutrons with electrons orbiting in levels of high probability
Explanation:
i think the answer might be D
Please help me with my Chemistry homework!! I have so much homework to do for other classes and I’m so stressed so even answering one question would be amazing!!!
1. A graduated cylinder had an initial volume of water of 22 mL. After an iron nail is dropped into the cylinder, the water rises to 38 mL. What is the volume of the nail?
2. Ms.Chavez dropped a gold ring into a graduated cylinder filled with water. The water level was originally at 20 mL. Now the water is at 25mL. Ms.Chavez knows that means the volume of the ring is 5 mL. What else would she have to do to find the density of her ring? Explain.
3. A simple of liquid propanol has a volume of 20.0 cm*^3 and a mass of 15.0 g. What is the density of propanol? Write only your answer below.
Which part of project management involves determining possible risks?
Answer:
Resources
Explanation:
Answer:
Explanation:
M
:answer question number 5
Answer:
it is simple true and thanks for point
Answer:
True
Explanation:
TRUST:)
The speed in which the moon orbits the earth is 500 mph.
a. True
b. False
Answer: False
Explanation: The moon travels at 1.42 mph around the Earth.
Answer:
false
Explanation:
______ have trees with cones.
A. temperate rainforests
B. boreal forests
C. tropical rainforests
D. temperate deciduous forests
Answer:
D.
Explanation:
the atomic number tells us all of the following except ..
Answer:
b
Explanation:
The atomic number tells us all of the following except B. The order in which the elements were discovered.
What does the atomic number let you know?
The atomic number is the number of protons in the nucleus of an atom. The number of protons outline the identity of detail (i.e., an element with 6 protons is a carbon atom, no matter how many neutrons may be present).
What pieces of facts do the atomic number inform you?The atomic variety helps human beings discover factors in step with the variety of protons one atom of the element has. It essentially defines the element. while having a neutral rate, it also offers the variety of electrons the detail has (in one atom). while isotopes are a component, it would not completely exchange the atom.
Learn more about Atom at https://brainly.com/question/6258301
#SPJ2
Atoms and ions are all the same.
Answer:
Yes they are
Explanation:
pt Which of the following is an example of potential energy?
A. a rolling ball
B. a turning windmill
C. a compressed spring
D. a moving train
Answer:
C . a compressed spring
Please help this is chemistry.
Answer:
C
Explanation:
the rest are trends except for Electronegativity
How do you calculate wavelength and frequency?
Answer:
Wavelength can be calculated using the following formula: wavelength = wave velocity/frequency. Wavelength usually is expressed in units of meters. The symbol for wavelength is the Greek lambda λ, so λ = v/f.
Explanation:
Just a formula that's commonly used in biology.
The _____________ is similar to a vacumn cleaner because it cleans up cell waste.
a
endoplasmic reticulum
b
lysosome
c
mitochondria
d
cell wall
Determine a skier's velocity in km/h, if it takes her 1.7 min to ski down a
1.67 km slope.
Answer:
103
Explanation:
do not listen to the haters
An object has a mass of 67.4 ounces and a volume of 13.8 cups. What is the density? _______ oz/cup (your answer should *only* be a number, round to one decimal place if needed) *
Answer:
4.9
Explanation:
Given data:
Mass of object = 67.4 ounce
Volume = 13.8 cup
Density = ?
Solution:
d = m/v
d = 67.4 ounce/13.8 cup
d = 4.9 oz/cup
Thus, density of object is 4.9 oz/cup.
The number of atoms of an element in a chemical formula is given by the _________.
Answer:
Explanation: In a chemical formula, the symbols for each element in the compound are followed by subscripts that tell us how many of that element are in the compound. The subscripts that follow each element's symbol indicate how many of that element are in the compound. Notice how H is located in more than one place.
Explanation:
A piece of silver is heated and added to a styrofoam cup calorimeter containing 26.0 mL (the density of water is 1 g/mL) of water at 19 oC. The water reaches a maximum temperature of 44 oC after the metal was added. If the specific heat of the silver is 0.240 J/g oC and it started at 93.8 oC
Answer:
m(Ag) = 227.5g
Explanation:
...what is the mass of the piece of silver?
The heat given for the piece of silver is the same heat that is absorbed for the water, that is:
m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)
m is mass of water in solution: 26.0mL = 26g of water
And m(Ag) is the mass of Ag, our incognite.
C is specific heat (0.240J/g°C for Ag), and 4.184J/g°C for water
ΔT is change in temperature (93.8°C - 44°C = 49.8°C) for Ag ad (44°C - 19°C = 25°C)
Replacing:
m(Ag)×C(Ag)×ΔT(Ag) = m(Water)×C(Water)×ΔT(Water)
m(Ag)×0.240J/g°C×49.8°C = 26g×4.184J/g°C×25°C
m(Ag)* 11.952J/g = 2719.6J
m(Ag) = 227.5g
what are cons of viruses ?????? oh dont mind this i jus gotta get this out of my head dont stop pop tht pop tht mhm jus like tht mhm shake it shake it mhm work it work it!!!!!!!!!!!
Answer:
Viruses can weaken your immune system. They make you sick. Some could even cause death.
Explanation:
I hope this helped I heard that song I forgot the name lol
(?)Li2O + (?)H2O → (?)LiOH
what goes inside the question marks?
Answer:
(1)Li2O + (1)H2O → (2)LiOH
Hope this helps!
At a constant temperature, 2L of a gas at 4atm of pressure is expanded to 6L. What is the new pressure? Please show steps!!
Answer:
The answer is 1.33 atmExplanation:
The new pressure can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
Since we are finding the new pressure
[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]
From the question we have
[tex]V_2 = \frac{2 \times 4}{6} = \frac{8}{6} = \frac{4}{3} \\ = 1.333333...[/tex]
We have the final answer as
1.33 atmHope this helps you
You have 16.6 g of water at 40.2 C. How many Joules are needed to warm the water to 44.8 C?
Answer:
Q = 319.49 J
Explanation:
Given that,
Mass, m = 16.6 g
Initial temperature, [tex]T_i=40.2^{\circ} C[/tex]
We need to find the heat needed to warm the water to 44.8 °C. The formula that is used to find the heat required is given by :
[tex]Q=mc\Delta T\\\\Q=mc(T_f-T_i)\\\\Q=16.6\ g\times 4.184\ J/g^{\circ} C\times (44.8-40.2)^{\circ} C\\\\Q=319.49\ J[/tex]
So, 319.49 J of heat is needed to warm water.
The Tissues of vascular Plants are organized into more complex structures that carry out a Variety of functions in the plant what structure is formed by a Group of tissues that work together to carry out a Specific function
A) Cell
B) Organ system
C)Organism
D Organ
Answer:
D Organ
Explanation:
A group of tissues that work together to carry out a specific function is known as organ.
Life is organized into distinct levels. These organization makes it possible for certain cells which are the basic unit of life to carry out their respective function.
A group of cell that performs the same function are organized into tissues. A group of tissues that work together to carryout a specific function are known as organs. A group of organs that perform the same functions forms the organ systems.
As the complexity of an organism increases, so also is their organization of life.
How is a "decay event' recorded
please someone help me its due today thanks :D
Answer:
D
Explanation:
All of the above are great examples!
"Endothermic reactions are those which absorb heat during the reaction."