Pb has an atomic number of 82. It has an isotope Pb-207. The mass number is 207.
How many protons are in Pb 207?
O 82
125
O 207
none of these

Answers

Answer 1

Answer:

Number of protons = 82

Explanation:

Given data:

Atomic number of Pb = 82

Mass number of Pb-207 = 207

Number of protons = ?

Solution:

An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.

All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.

Atomic number of Pb = number of protons or electrons

82 = number of protons or electrons

Mass number = Number of protons + number of neutron

207 = 82 + number of neutron

Number of neutrons = 207 - 82

Number of neutrons = 125


Related Questions

what is the mass of 2.50 mol of (C3H5)2S

Answers

Hey there!

We need to start this by finding the molar mass of (C₃H₅)₂S.

This molecule consists of 6 carbon atoms, 10 hydrogen atoms, and one sulfur atom. We need to add the molar masses of each atom up.

C: 6 x 12.01 = 72.06

H: 10 x 1.008 = 10.08

S: 1 x 32.07 = 32.07

-------------------------------

                    114.21 g/mol

Ok, now that we have established that the molar mass of (C₃H₅)₂S is 114.21 g/mol, we have 2.50 mol of (C₃H₅)₂S. If 1 mol has a mass of 114.21 g, then 2.50 mol will have a mass of 2.50 time 114.21.

2.50 x 114.21 = 285.525 grams

This should go to just three significant figures, so:

The mass of 2.50 mol of (C₃H₅)₂S is 286 grams.

Hope this helps!

What is the wavelength of an electromagnetic wave that travels at 3 x 10^8 m/s and has a frequency of 60 mhz? (1 mhz = 1,000,000 hz)?

Answers

Answer:

5m

Explanation:

Given parameters:

Speed of wave  = 3 x 10⁸m/s

Frequency  = 60mhz  = 60 x 10⁶Hz

Unknown:

wavelength = ?

Solution:

To solve this problem;

 we use the expression:

                      V = F ∧  

V is the velocity

F is the frequency

∧ is the wavelength

  Now insert the parameters and solve;

              3 x 10⁸   = 60 x 10⁶ x ∧  

 So;

        ∧   = 5m

what do you know about periodic tables ?

Answers

Answer:

That it's really hard to remember and it's filled with elements

Explanation:

NHa is an
example of
O an element.
O a mixture.
O a compound
O an atom.

Answers

Answer:

what is the question

Explanation:

Answer:

COMPOUND

Explanation:

I THINK

How many moles of carbon would 50.0 g of carbon represent?​

Answers

Answer:

600 grams

Explanation:

The value of the mole is equal to the number of atoms in exactly 12 grams

12x50=600

12. What is the mass number of an atom that has 4 protons, 4 electrons, and 5 neutrons?

Answers

Answer:

9

Explanation:

mass number = protons + neutrons

= 4 + 5 = 9

Help me if u good at science:)



How are mass and weight alike?
O A. Both are measured in pounds.
B. Both depend on how much matter an object has.
C. Both change with gravitational force.
OD. Both are the same everywhere in the universe.

Answers

Answer:

I belive it is B

c. both change with gravitational force

HELP ASAP
Which is involved in the formation of sinkholes?
O acidic rainwater
O
mining
O rising sea level
winds

Answers

Answer:

Sinkholes this is the answer

Answer:

B. Mining

Explanation:

trust

The net charge on a sulfide ion (S2-) is
-2. Explain how this ion obtains its
charge. Your answer
should include a discussion of
subatomic particles.

Answers

Explanation:

A sulfide ion S²⁻ is formed from sulfur atom.

An ion is an atom that has lost or gained electron.

Sulfur atom is made up of 16 electrons according to its position on the periodic table.

In essence, there are 16 negatively charged particles in an atom of sulfur.

Also, in the neutral or uncharged state, the number of electrons equals to the number of protons.

So, there are 16 electrons and protons in an atom of sulfur.

Every atom tends to be like the noble gases. Noble gases have complete octets. So, for sulfur to have a complete octet, it must gain two more electrons to be isoelectronic with Argon. Now, the number of electrons becomes 18;

 Charge  = Number of protons  - Number of electrons

 Charge  = 16  - 18  = -2

PLEASE HELP HELP I NEED THIS ASAP

Answers

Wait SORRY HELP WITH WHAT?!!
The hydrogen-ion concentration is 1000 times greater.

Please help i cant find any answers...

Using the balanced equation below,
how many grams of cesium xenon
heptafluoride would be produced
from the complete reaction of 37.8 g
cesium fluoride?
CSF + XeF6 CsXeF7

Answers

Answer:

98.8

Explanation:

CsF + XeF6 --> CsXeF7

37.8g ................. ?g

37.8g CsF x (1 mol CsF / 151.9g CsF) x (1 mol CsXeF7 / 1 mol CsF) x (397.2g CsXeF7 / 1 mol CsXeF7) = 98.8g CsXeF7 .......... to three significant digits

Answer:

28.0

Explanation:

True or False, In a neutral atom, the number of protons is equal to the number of neutrons

Answers

Answer:

False

Explanation:

In a neutral atom, the number of protons is not necessarily equal to the number of neutrons.

In such atom, the number of protons is equal to the number of electrons.

Protons are the positively charged particles in an atom. Electrons are the negatively charged particles in an atom. Neutrons do not carry any charges.

When the number of protons and electrons are the same, a neutral atom is formed.

name the compound formed when pottasim reacts with bromine

Answers

Answer:

the answer is potassium bromide

Answer:

POTASSIUM BROMIDE

Explanation:

At room temperature, potassium reacts with bromine, and by synthesis, this compound is formed. The chemical equation of this reaction is 2 K + Br2 = 2KBr. Potassium bromide has an immense contribution to medical science.

If an object what is 30 kg of mass is moving at 10 m/s to the right how much kinetic energy does it have

Answers

Explanation:

m=30

v=10

K.E=1/2mv^2

=1/2×30×10^2

=1/2×30×100

=1500 joule


3. Heating by direct contact between particles is called

Answers

I believe it is “Conduction” im not 100% sure tho, I haven’t done this since the 7th grade.

How many atoms are in 0.00100 mole of Na?

Answers

There rlly isn’t noooo number so what do you expect of course it would be zero. 0£

Answer:

6.02x10^23 atoms  i think

Explanation:

Can some answer this please?


Which of these describes a chemical property of a substance?

A. Sugar's tendency to dissolve in water

B. Paper's tendency to tear

C. Gold's tendency to stay shiny

D. Wax's tendency to melt at 37 Celsius

Answers

Answer:

i think its C

Explanation:

Wax's tendency to melt can describe a chemical property of a substance. Therefore, option (D) is correct.

What is a chemical property?

A chemical property can be described as any of a material's properties that becomes evident during a chemical reaction. Any quality can be established only by changing the chemical identity of the substance. Chemical properties cannot be evaluated by viewing or touching the substance.

The internal structure of the substance must be affected greatly for its chemical properties to be investigated. When a substance undergoes a chemical reaction, its properties will change drastically, resulting in a chemical change.

Chemical properties are contrasted with physical properties and can be used for building chemical classifications. They are also useful to identify an unknown substance.

As the wax melt, it also burns and hives the carbon dioxide, water, heat, and light. Therefore, the wax's tendency to melt and burn is a chemical property.

Learn more about chemical property, here:

https://brainly.com/question/1935242

#SPJ2

Sn + 2Ha -> SnCl2 + H2
a. synthesis
b. single replacement
C. combustion
d. double replacement
e decomposition

Answers

Answer:

your question is totally wrong. there is no cl2 in reactants.

Are the pieces of paper natural or charged?

Answers

Their are natural since they come from trees which is natural

Answer:

natural

Explanation:

I need help pls and thank you

Answers

it’s 1 mark k/u thanks

what partie is found outside of the nucleus​

Answers

Answer:

Electrons

Explanation:

Answer:

electrons

Explanation:

6. Steel is a metallic-like material but it is not a pure element. It is a alloy.
True
False

Answers

Answer:

true

hope this helps! have an amazing day!

3 CACO3+2H3PO4>CA3(PO4)2+3 CO2+3 H2O

Answers

Answer:

its hto-567-st-3=56+78=103

Explanation:

so103 is yo answer

12. What are two different ways to turn a turbine to generate electricity without using fossil
fuels?
HELPP

Answers

Answer:

two different ways are 1st by using water and 2nd by using wind these also not harm our environment

How much energy is required to raise the temperature of 0.2 kg of aluminum
from 15°C to 18°C?
5382 J
B. 538 J
C. 600 J
D. 179 J

Answers

B. 538 j hoped this helps

Periodic Table Puzzle Test

Answers

Answer:

dfmpfndtngognjf

Explanation:

Which of these common substances is a homogeneous mixture?
O
A. table salt
B. pure water

C. whole milk
D. maple syrup

Answers

Answer:

whole milk ,table salt , maple syrup

Answer:

d

Explanation:

Balance the given
equation
SnO → Sn + O2
Sn
Sn
О
O

Answers

Explanation:

the balanced equation is: .........

Answer:

i agree with her/him^^^^^^^^^^^^^^^^^^^^^^

Explanation:

Find the average atomic mass for boron if 19.9% of boron atoms have a mass of 10.0129371 amu and 80.1% have a mass of 11.0093055 amu. Round to 3 significant figures.

Answers

Answer:

Average atomic mass  = 10.8  amu

Explanation:

Given data:

Average atomic mass = ?

Percentage of boron having mass 10.0129371 amu = 19.9%

Percentage of boron having mass 11.0093055 amu = 80.1%

Solution:

Average atomic mass  = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)  / 100

Average atomic mass  = (19.9×10.0129371 )+(80.1×11.0093055) /100

Average atomic mass =  199.3 + 881.8 / 100

Average atomic mass = 1081.1  / 100

Average atomic mass  = 10.8  amu.

When a molecule loses or gains an electron it becomes

Answers

When a molecule loses or gains an electron it becomes an ion.

"If it gains a negative electron, it becomes a negative ion. If it loses an electron it becomes a positive ion."

Answer:

the molecule become an iron

Explanation:

have a great day

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