Answer:
Most reactions occur quickly after ingestion or contact with the allergen, but some can occur up to a few hours later. There can also be a second phase of the reaction when symptoms reoccur. It is important to keep an eye on your child for about 6-8 hours following the first reaction.
Explanation:
PLEASE LHELP
How many oxygen atoms are in 6 Carbon dioxide compounds (6co2)
Number 5
PLEASEE HELP
Answer:
12
Explanation:
6 moles multiplied 2 atoms of O2
That gives 12 atoms
Someone pls help me I will make you brain
Answer:
D cooler temperatures
Explanation:
Make me b r a i n please
how many protons does boron-11 atom have
Answer:
5
Explanation:
Give an example of a type of cookie that is a heterogeneous mixture, and a type of cookie that is a homogeneous mixture. Explain your reasoning.
plz answer
I need help I don’t understand it and I need it done before the end of today
Answer:
May be trial 2..................
Aluminum chlorohydrate, al2(oh)5cl, is an active ingredient in some antiperspirants. what is the mass percent of aluminum in this compound?
30.93%
15.26%
39.48%
21.75%
Magnesium has an atomic (proton) number of 12 and a mass number of 24.
How many magnesium atoms are there in 2 moles of magnesium? HELPPPPP
Answer:
1.2044x10^24 atoms
Explanation:
one mole of any element has 6.022x10^23 atoms
so 2 moles is just multiplying avogadros number by 2
2 x ( 6.022x10^23)= 1.2044x10^24 atoms
A landslide carries many tons of rock from a hillside into a valley. All of the plants in the valley are buried. New plants that begin to grow in the valley after the landslide will MOST LIKELY lack —
Answer: c
Explanation: i got a 100 on the test
using the standard enthalpies of formation, what is the standard enthalpy of reaction?
Answer:
This equation essentially states that the standard enthalpy change of formation is equal to the sum of the standard enthalpies of formation of the products minus the sum of the standard enthalpies of formation of the reactants. and the standard enthalpy of formation values: ΔH fo[A] = 433 KJ/mol.
Explanation:
Hope this helps.
microfilaments are composed of ____________ in ____________ arrangement.
Explanation:
microfilaments are composed of repeating actin subunits in a thin double-helix arrangement.
Help me pls I will mark you as brain
pls help me on this I have 5 minutes left to submit
#1
Heterogenous mixture mean unsimilar substances .
Chicken noodle soyp.salt waterpropane.#2
An element is a substance made of only one type of atoms
Example-Al,SI need the anwer plz helppp this question is worth 25 point
Explanation:
Enzyme X works on sugar C substrate.
How do we get mass from moles?
Think of a time you might have used the scientific method without even realizing it.
Answer:
when i exist
Explanation:
Which substance tends to form anions when bonding with other elements?
sodium
oxygen
argon
calcium
Answer:
B) Oxygen
Explanation:
i just took the test.
Any species that contain negative charge over it called anion. Out of sodium, oxygen, argon and calcium, oxygen is the only element that can form anion. So option B is correct option.
What are non metals?Non metals are the element that have property to gain electron. When any element gain electron then element attain negative charge and that element is called anion.
In our question sodium, argon belongs to metals category and these lie on the left side of the periodic table. Metals are meant to release electron and hence become cation.
Argon is non metal but it is a noble gas which has property to not to react as its octet is complete. Thus the only element that is non metal here is Oxygen that forms anion. Its oxidation state is -2. Thus option b is correct option
To learn more about non metals, here:
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The energy of motion is known as potential energy.
Question 1 options:
True
False
Answer:
False
Explanation:
This is because potential energy is energy that it not used yet.
before making a covalent bond, where do the atom's electrons spend most of their time?
Answer:
Before bonding, the atom's electrons spend most of their time around the nuclei of each atom. Once bonded, the electrons spend most of their time between the two nuclei
7th grade Sem 1
13.2.6 Quiz: Chemistry of Life
Question 3 of 5
Which substance used during photosynthesis does a plant take in from the
soll?
A. Water
O
B. Sugars
C. Proteins
D. Oxygen
SUBMIT
Answer: Water
Explanation: During photosynthesis, plants take in carbon dioxide (CO2) and water (H2O) from the air and soil
Phosphorus-32 has a half-life of 14.3 years. How many grams remain after 57.2 years if you have
4.0 g of the isotope at the beginning?
Answer:
29.3 years to live
Explanation:
Phosephurus loses 32 years at his life -32
then he gains 14.3 years back and another 57.2 years
totaling 29.3 years he will live
Potential energy is energy that is stored in an object. It isn't being used at the moment, but is waiting to do work. A good example is to think about a boulder sitting on top of a hill. Just sitting there, the boulder isn't doing anything. But because it is sitting on top of a hill, it has the potential to roll down and do some damage to a car or building below. The energy is stored in that rock because of its size (mass) and the distance it will travel once it starts rolling. Another good example is a rubberband. When you stretch a rubber band, it wants to move back to its original position, and thus you have given it potential energy. As the rubber band is released, potential energy is changed to motion.
Kinetic energy is energy of motion. A rubber band flying through the air has kinetic energy. When you are walking or running your body is exhibiting kinetic energy. This energy is performing work. Other examples of kinetic energy include: legs pump bicycle pedals, lightning snaps trees, cars travel down the street, football players making tackles, and 4-wheelers speeding through the woods.
Potential energy is converted into kinetic energy. As mentioned before, a stretched rubberband can change from having potential to kinetic energy. Another example of this change between kinetic and potential energy can be seen using a yo-yo. Before a yo-yo begins to fall from your hand it has stored energy due to its position. At the top (in your hand) it has its maximum potential energy. As it starts to fall the potential energy begins to be changed into kinetic energy. At the bottom its potential energy has been completely converted into kinetic energy so that it now has its maximum kinetic energy. Another example of the change between kinetic and potential energy is a waterfall. A waterfall has both potential and kinetic energy. The water at the top of a waterfall has stored potential energy. When the water begins to fall, its potential energy is changed into kinetic energy. This change in energy is used in Niagara Falls, Canada to provide electricity to parts of the northeastern United States.
Questions:
1. What is kinetic energy?
2. What is potential energy?
3. List 5 examples of Potential energy given in the above passage. The first two are filled in for you.
1. __A boulder sitting on top of a hill that could roll down.___________ 2. __A stretched rubberband.___________________________________ 3. ________________________________________________________ 4. ________________________________________________________ 5. ________________________________________________________
4. List 5 examples of Kinetic Energy given in the passage above. The first
two are filled in for you.
1. __Water falling down a waterfall.____________________________ 2. __Car moving through the streets.____________________________ 3. ________________________________________________________ 4. ________________________________________________________ 5. ________________________________________________________
Answer:
it's all in the passage
Explanation:
read over the passage and find the answer i promise they're in there.
what is physical change
Answer:
changes that dont result in the formation of new substance with new properties.
Calculate the mass of a substance which has a volume of 35
cm3 and a density of 0.500 g/cm3. Make sure your answer
has correct significant figures.
The answer is 17.5kg.
To get the mass of an object you do Volume × Density. The SI unit of Mass is "kg."
I will brainless who can answer this all pleaseeeeej
Answer:
1. FALSE
2. TRUE
3. TRUE
4. FALSE
5. FALSE
6. TRUE
7. TRUE
8. TRUE
9. TRUE
10. TRUE
Explanation:
1. Conduction occurs more readily in solids and liquids
2. Gold is used as a contact metal in the electronics industry as it is a good conductor of both electricity and heat.
3. None
4. Radiation is the fastest mode of heat transfer while conduction is the slowest mode of heat transfer
5. Heat from Sun reaches us by the process of radiation
6. None
7. It is the motion of particles that creates a form of energy called heat (or thermal) energy that is present in all matter
8. At a temperature of 0o C, the thermal energy within a given system is also zero
9. None
10. None
PLEASE MARK BRAINLIEST, THANKS <3
a substance composed of two or more metals.
Answer:
A substance composed of two or more metals is called an alloy
Explanation:
The atoms of which elements tend to gain electrons? Which tend to lose electrons?
A.Metals tend to lose electrons; nonmetals tend to gain electrons.
B.Metals tend to gain electrons; nonmetals tend to lose electrons.
C.Most metals and nonmetals tend to lose electrons; metalloids tend to gain
electrons.
D.Metals and most nonmetals tend to lose electrons; noble gases tend to gain
electrons.
Answer:
Nonmetals tend to gain electrons and metals tend to lose electrons.
Explanation:
Density is a ___ that ____ the ____ of an object to its ______
Answer:
matter , equals , weight , size
A nickel compound has the formula Ni(NO3)2•xH,0 and a molar mass
of 290.7 g mol-1. Calculate the value of x.
Someone tell me the method for this
Explanation:
Molar mass of a compound is the sum of the molar mass of all the atoms of the compound.
⇒ Molar mass of the Nickel Compound (Hydrated Nickel (II) Nitrate)
= Molar mass (Ni+ 2N + 6O)+ x (2H+ O)
= [58.693 + 2(14.007) + 6(15.999)] + x [2(1.008) + 15.999] g/mol
= (182.701 + 18.015x) g/mol
Since the molar mass is known to be 290.7 g/mol
then 182.701 + 18.015x = 290.7
⇒ 18.015x = 290.7 - 182.701
x = (290.7 - 182.701) ÷ 18.015
∴ x = 6 [conventionally expressed as a whole number]
that makes the compound Nickel Nitrate Hexahydrate
The value of x in the hydrated compound of nickel nitrate with molecular mass 290.7 g/mol is 6.
What is the molecular mass?Molecular mass can be defined as the sum of the mass of each element in the compound.
The molecular mass of the given compound is 290.7 g/mol. The value of x in the compound can be given as;
[tex]\rm 290.7\;g/mol=2(Ni)+2(N)+2(3O)+x(2H+O)[/tex]
Substituting the mass of N, Ni, O and H for the calculation of x as:
[tex]\rm 290.7\;g/mol=(58.693)+2(14.007)+2(3(15.999))+x(2(1.008)+15.999)\\290.7=182.701+18.015x\\x=6[/tex]
The value of x in the hydrated compound of nickel nitrate is 6.
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how many valence electrons does alkali metals gain or lose
Answer:
Alkali metals have 1 valence electron on their outer shell. They are more stable when they have 8 valence electrons, so they want to lose that valence electron. They do this by bonding with other elements. When they lose their 1 valence electron, they have a full octet and are therefore stable.:
Convert 3,124,991 centimeters (cm) to miles (mi) rounding to 4 sig figs
Answer:
19.417794 mi
Explanation:
Answer:
19.41
Explanation: