A neutral atom of beryllium (Be) has an average mass of 9 amu and 4 electrons. How many neutrons does it have?
13
5
9
4
Answer:
It has 5 neutrons
Explanation:
The fact that it is a neutral atom tells us that the number of electrons and protons is the same:
The problem tells us there are 4 electrons, thus there are 4 protons.The average mass of an atom is the sum of the number of protons and the number of neutrons:
Mass = # Protons + # NeutronsWith the above information in mind we can calculate the number of neutrons:
9 amu = 4 Protons + # Neutrons# Neurons = 5 NeutronsPLEASE HELP IM GOING TO GIVE BRAINLY AND A LOT OF POINTS
Answer:
1)
a- 0.10 mol
b- 0.078 mol
c- 5454.54 mol
d- 0.160 mol
e- 0.022 mol
2)
a) 3.6 g
b) 14.9 g
c) 5.6 g
d) 39.9 kg
e) 6.8 g
3)
a) 28
b) 40
c) 160
d) 28
e) 249.6
What is the molar mass of the anhydrous compound? Answer using four significant figures.
36.02 g/mol
120.15 g/mol
156.12 g/mol
Answer:
120.15
Explanation:
ta edg
Answer:
120.15
Explanation:
edg 2021
. Which laboratory equipment would most likely be used for testing a substance for the presence of monosaccharides? *
Answer:
Benedict's reagent is the indicator we use to detect monosaccharides. When monosaccharides are mixed with Benedict's and heated, a color ange occurs.
Hope this helps!! :)
Different isotopes are matched with their uses as (i) Co- 60- To treat cancer (ii) U- 238- To produce electricity (iii) I-131- To treat goitre (iv) Na- 24- In agricultural research Which of the below matches are correct? (i) and (ii) (ii) and (iii) (iii) and (iv) (i) and (iii)
Answer:
I-131- To treat goitre
U- 238- To produce electricity
(ii) (ii) and (iii)
Explanation:
Radioisotopes have various applications in science. These applications may be positive or negative.
I-131- is used to treat goitre. This is a very important medical application of this isotope of iodine.
U-238 is ordinarily non-fissile but can be transformed to Pu-239 and used as a nuclear fuel for electricity generation.
Match the intermolecular force with the physical property that will result
Answer:
Intermolecular forces are the forces that bind two molecules together. Physical properties are affected by the strength of intermolecular forces. Melting, boiling, and freezing points increase as intermolecular forces increase. Vapor pressure decreases as intermolecular forces increase. Hope this is what your looking for!
Explanation:
Brainliest please?
help me id.k this. this is so hard...
Answer:
it's 2:1
ask me if you want explaination also. it is just an mcq that's why i am not giving
thank you
Above which temperature does the thermal conductivity of water start to fall?
Answer:
It’s actually 130 degrees Celsius.
Explanation:
An organism is unicellular, reproduces asexually, and lives in a hot hydrothermal vent at the bottom of the ocean. This organism most likely belongs to the kingdom
For the problem: Mg (s) + O₂ (g) ➞ MgO (g) if 4.3 g of magnesium reacts with 83 g of oxygen (O₂), which is the limiting reagent? *
4 points
magnesium
oxygen
magnesium oxide
dimagnesium dioxide
Explanation:
hope this can help youuu
Determined which equation is balanced or unbalanced.
Answer:
1. balanced
2.unbalanced
3.unbalabced
4.balanced
What is the chemical formula for zinc (II) phosphate?
Answer:
Zn^3(PO4)2
Explanation:
thats the formula
The chemical formula for compound zinc (II) phosphate is Zn₃(PO₄)₂.
Zinc (II) phosphate is an inorganic chemical compound that is made up of zinc cations and phosphate anions .The chemical formula for zinc (II) phosphate is obtained by combining three zinc cations with two phosphate anions to achieve the neutral charge.
Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
Thus, chemical formula for compound zinc (II) phosphate is Zn₃(PO₄)₂.
Learn more about chemical formula,here:
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At 313° K, the volume of a gas is 50.0 ml. At constant pressure, what is the new volume of the
gas if the temperature is decreased to 293°K?
Answer:
46.80 ml
Explanation:
V1 =50ml
T1 =313K°
T2 = 293K°
V2 =?
V1/T1 =V2/T2
V2=V1*T2/T1
V2=50*293/313
46.80ml
What do radio waves and microwaves have in common?
O Both have shorter wavelengths than visible light
O Both are at the side of the spectrum that has the highest frequency
O Both have lower frequencies than visible light
O Both have radiant energy than visible light.
Answer:
The last one
Explanation:
Magnesium is a metal that is commonly used in products that need to be lightweight. Suppose a 2.00-kg piece of magnesium has 8160 J of energy added to it. Its temperature increases 4k. What is the specific heat of magnesium. Show your work
Answer:
The specific heat of magnesium is 1.02 J/g.K
Explanation:
To calculate the energy involved in the heating of the metal (magnesium), we use the following expression:
energy = mass x Cp x ΔT
We have the following data:
mass = 2.00 kg x 1000 g/1.00 kg = 2000 g
energy = 8160 J
ΔT = 4 K
Thus, we can calculate the specific heat of magnesium (Cp) in J/g.K as follows:
⇒ Cp = energy/(mass x ΔT) = 8160 J/(2000 g x 4K) = 1.02 J/g.K
plzzz helppppppp!!!!!!!!!!!♥️♥️i only have 2 mins to complete this!!!!
Count the number of elements in the following molecule: 3 C2(H6K5)2
Answer:
3 elements
Explanation:
Carbon, helium, and potassium
2. Balance the following equations. If an equation is already balanced, say so in
your answer.
a. Cl2 + Br → Cl + Br2
b. CaO + H20 + Ca(OH)2
C. Na2SO4 + BaCl2 → BaSO4 + NaCl
d. ZnS + 02 → ZnO + SO2
e. Cl2 + KBr → KCl + Br2
f. H2SO4 + NaOH → Na2SO4 + H20
BRAINLIEST BRAINLIEST
Please answer
What are the three main compositional layers of the Earth
Answer:
The Earth is divided into three chemical layers: the Core [Inner Core (D) and Outer Core (C)], the Mantle (B) and the Crust (A).
Explanation:
How many atoms are in the chemical formula shown? HCIO3
Answer:
5
Explanation:
chemical formulas show what atoms are in a molecule. In this case there is 1 hydrogen (H), 1 chlorine (Cl), and 3 oxygens (O). The 3 behind the oxygen is a subscript and tells us that there are 3 oxygen atoms.
Another example is H2O which as 3 atoms. 2 hydrogens (H) and 1 oxygen (O). This formula has a subscript 2 behind the hydrogen showing that there are 2 hydrogens.
true or false, the melting point of gold is more than 1,000°c
Answer:
Explanation:
true it is 1064 c
Answer:
true
Explanation:
it's 1064º C
An unknown metal with a mass of 585.6 grams, changes temperature from 46.5°C to 84.5°C when it absorbs 795J of energy. Find specific heat of the unknown metal.
Answer: So the answer would be um I dont
know the answer right now but message me later on and I will help
Explanation: The equation that relates heat (q) to specific heat (c_p) , mass (m), and temperature change (Delta{T}) is shown below.
q=c_p times m times Delta{T} The heat that is either absorbed or released is measured in joules. The mass is measured in grams. The change in temperature is given by Delta{T}= T_f - T_i , where T_f is the final temperature and T_i is the initial temperature. Step 1: List the known quantities and plan the problem .
Known
heat = q = 134 J
mass = m = 15.0 g
Delta{text{T}} = 62.7^circ text{C} - 24.0^circ text{C} = 38.7^circ text{C}
Unknown
c_p text{of cadmium}= ? text{J}/ text{g}^circ text{C}
The specific heat equation can be rearranged to solve for the specific heat.
Step 2: Solve .
c_p=frac{q}{m times Delta{T}}=frac{134 text{ J}}{15.0 text{ g} times 38.7^circ text{C}}=0.231 text{ J/g}^circ text{C}
Step 3: Think about your result .
The specific heat of cadmium, a metal, is fairly close to the specific heats of other metals. The result has three significant figures.
Since most specific heats are known, they can be used to determine the final temperature attained by a substance when it is either heated or cooled. Suppose that a 60.0 g sample of water at 23.52°C was cooled by the removal of 813 J of heat. The change in temperature can be calculated using the specific heat equation.
Delta{T}=frac{q}{c_p times m}=frac{813 text{ J}}{4.18 text{ J/g}^circ text{C} times 60.0 text{ g}}=3.24^circ text{C}
Since the water was being cooled, the temperature decreases. The final temperature is:
T_f=23.52^circ text{C} - 3.24^circ text{C}=20.28^circ text{C}
Mechanical advantage = load/_______
Answer:
Mechanical advantage = load/effort
Explanation:
Mechanical advantage is like a ratio of load to effort and many machines like pulleys depend on this relationship between load and effort for it to work.
Answer:
The formula of mechanical advantage is Load÷effort
Explanation:
Mechanical advantage is the ratio of the load to the effort i.e. MA=Load(L)÷Effort(E)
What is the density of butane (C4H10) at STP?
Help please
Answer:
his means 1 mole of butane has a volume of 22.4dm3 at STP. 1 mole of butane has the same mass in grams as its relative molecular mass.
Part C
In the Options window of the simulation, select Pie to show the pie chart. In the window labeled Start with how many, use the up arrows to add 40 particles of A and 40 particles of BC. Then press the Begin experiment button. Wait a few seconds for the reaction to come to equilibrium, and then click pause near the bottom of the screen.
Study the graph on the left. The green line shows total average energy. The blue line shows the amount of potential energy possessed by the reactants and the products. Recall that substances most readily take the form in which they have the least potential energy. The amount of potential energy can be adjusted, affecting the outcome of the reaction. Recall that in the initial experiment for synthesizing ammonia, only about 20% of the reactants were converted to the products.
Click the Play arrow to resume the simulation. Then adjust the potential energy curve so the proportion of reactants to products is roughly the same as the proportion in the initial experiment. Adjust the center slider up or down so there’s a bump in the middle of the energy curve. The bump represents the energy the particles must have to react. Take a screenshot of the energy curve, and use the Insert Image button to paste it in the answer space.
Answer:
Explanation:
I'm not going to lie, I think I did this completely wrong. But you can use this. I was completely lost on this assignment.
Answer:
I believe this is the answer
Explanation:
What is a biotic factor
Answer:
can be described as any living component that affects another organism or shapes the ecosystem.
Explanation:
....Which is the best classification for West Nile virus?
food-borne illness
irradiated disease
antibiotic resistant bacteria
emerging infectious disease
Answer:
D.
Explanation:
Emerging infectious disease
Answer:
d
Explanation:
emerging infectious disease
How many molecules are in 1200 g of acrylonitrile (C3H3N), a chemical used in the production of plastic
Help
Answer: [tex]136.2\times 10^{23}[/tex] molecules
Explanation:
According to avogadro's law, 1 mole of every substance contains avogadro's number of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}=\frac{1200g}{53.06g/mol}=22.62moles[/tex]
1 mole of acrylonitrile has = [tex]6.023\times 10^{23}[/tex] molecules
Thus 22.62 moles of acrylonitrile has = [tex]\frac{6.023\times 10^{23}}{1}\times 22.62=136.2\times 10^{23}[/tex] molecules
Taking into account the definition of Avogadro's number, 1.36×10²⁵ molecules of C₃H₃N are in 1200 g.
Avogadro's NumberAvogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.
Mass molarThe molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.
The molar mass of a compound (also called Mass or Molecular Weight) is the sum of the molar mass of the elements that form it (whose value is found in the periodic table) multiplied by the number of times they appear in the compound.
This caseIn this case, you know the molar mass of the elements is:
C= 12 g/moleN= 14 g/moleH= 1 g/moleSo, the molar mass of the compound C₃H₃N is calculated as:
C₃H₃N= 3× 12 g/mole + 3× 1 g/mole + 14 g/mole
Solving:
C₃H₃N= 53 g/mole
You have 1200 g of C₃H₃N. So, knowing its molar mass, you can calculate the number of moles that contain a mass of 1200 g as:
1200 g×[tex]\frac{1 mole}{53 grams} [/tex]= 22.64 moles
Then you can apply the following rule of three: If by definition of Avogadro's number 1 mole of C₃H₃N contains 6.023×10²³ molecules, 22.64 moles of C₃H₃N contains how many molecules?
amount of molecules of C₃H₃N= (22.64 moles × 6.023×10²³ molecules)÷ 1 mole
amount of molecules of C₃H₃N= 1.36×10²⁵ molecules
Finally, 1.36×10²⁵ molecules of C₃H₃N are in 1200 g.
Learn more about
Avogadro's Number:brainly.com/question/11907018?referrer=searchResultsbrainly.com/question/1445383?referrer=searchResultsbrainly.com/question/1528951?referrer=searchResultsMolar mass:brainly.com/question/12695086?referrer=searchResultsin which of the following is the symbol for the ion and the number of electrons it contains given correctly? *
Answer:Number of electrons that are present in an atom is determined by the electronic configuration of that atom.
If an ion is carrying a positive charge, it means that the atom has lost electrons and if an ion is carrying a negative charge, it means that the atom has gained electrons.
For the given options:
Option A: The atomic number of hydrogen atom is 1 and the electronic configuration for ion will be:
Thus, this atom does not have any electrons.
Option B: The atomic number of bromine atom is 35 and the electronic configuration for ion will be:
Thus, this atom has 36 electrons.
Option C: The atomic number of aluminium atom is 13 and the electronic configuration for ion will be:
Explanation:
Determine the molar mass of Ze(NO3)2. (Ze=55.85 N=14.01 O=16.00) *
Help
Answer:
179.87 g/mol
Explanation:
First you need to determine the number of each elements in the molecule. This information comes from the molecular formula.
Ze(NO3)2 tells us that there is 1 Ze atom and 2 NO3 anions per molecule. each NO3 anion will have 1 nitrogen and 3 oxygens. Due to that, one molecule of Ze(NO3)2 will have 1 atom of Ze, 2 atoms of nitrogen (N), and 6 atoms of oxygen (O).
Next you need to add all of the individual atom's molar masses to get the over all molar masses. The molar masses of each element is in the question but it can also be found on the periodic table.
molar mass of Ze(NO3)2 = 55.85g/mol + (14.01g/mol*2) + (16.00g/mol*6)
molar mass of Ze(NO3)2 = 179.87 g/mol
I hope this helps.
hey guys can u help me ASAP its on science
Answer:
The answer to your question is A - electrons
Explanation:
To be honest it's pretty obvious, none of the other things could possibly come with valence behind it so electrons is the only logical answer.
Answer:
A. electrons
Explanation:
The valence electrons on the valence shell which is the last layer of electrons are the same for atoms in the same column.