1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Ulleksa [173]
3 years ago
8

What is the mass number of 207Pb ? A: 289 B: 207 C: 125 D: 82

Chemistry
1 answer:
Sergio [31]3 years ago
3 0
207 is the mass number. 82 would be the atomic number
You might be interested in
5. True or False: If one thing in a food web is affected, it will only probably affect the organism that directly relies on it f
34kurt
A because if something happened to that organism then the organism relying on it will either go extinct or just die out due to starvation
8 0
3 years ago
State Hess' law of constant heat summation.
AveGali [126]

Answer:

-74.6 kj/mol

Explanation:

you can see the answer at the pic

8 0
3 years ago
The total volume of seawater is 1.5 x 10²¹ L. Seawater contains approximately 3.5% sodium chloride by mass. At that high of a co
garri49 [273]

Answer:

There are 5.408\times 10^{22} grams contained in all the seawater in the world.

Explanation:

At first let is determinate the total mass of seawater (m_{sw}), measured in grams, in the world by definition of density and considering that mass is distributed uniformly:

m_{sw} = \rho_{sw}\cdot V_{sw}

Where:

\rho_{sw} - Density of seawater, measured in grams per liters.

V_{sw} - Volume of seawater, measured in liters.

If V_{sw} = 1.5\times 10^{21}\,L and \rho_{sw} = 1030\,\frac{g}{L}, then:

m_{sw}=\left(1030\,\frac{g}{L} \right)\cdot (1.5\times 10^{21}\,L)

m_{sw} = 1.545\times 10^{24}\,g

The total mass of sodium chloride is determined by the following ratio:

r = \frac{m_{NaCl}}{m_{sw}}

m_{NaCl} = r\cdot m_{sw}

Given that m_{sw} = 1.545\times 10^{24}\,g and r = 0.035, the total mass of sodium chloride in all the seawater in the world is:

m_{NaCl} = 0.035\cdot (1.545\times 10^{24}\,g)

m_{NaCl} = 5.408\times 10^{22}\,g

There are 5.408\times 10^{22} grams contained in all the seawater in the world.

8 0
3 years ago
Which defines health?
NARA [144]
I mean this is pretty obvious it's D. life expectancy is sort of close but not really. B is close too but it's not it bc that's not what health is. you could be over weight and not be sick and it still isn't healthy. and C isn't close at all. hope this helps, have an amazing day :)
7 0
3 years ago
¿Por qué crees que es importante conocer nuestra condición económica antes de practicar actividades físicas regularmente?
gogolik [260]

Answer:

el ejercicio físico ayuda a gente a perder peso y reduce el riesgo de desarrollar algunas enfermedades. el ejercicio físico regular el reducen los riesgos de ciertas enfermedades como obesidad, diabetes tipo 2 e hipertensión el ejercicio físico puede ayudar a mantener el cuerpo en un peso saludable pero a veces algunos tienen enfermedades al corazón o asma y les afecta a ser demasiado práctica esa actividad

3 0
3 years ago
Other questions:
  • If 97.7 ml of silver nitrate solution reacts with excess potassium chloride solution to yield 0.326 g of precipitate, what is th
    12·1 answer
  • Which of the following is not true of a scientific theory?
    13·1 answer
  • If constant heat is added to ice water, what changes will take place and at what temperatures?
    6·1 answer
  • Fill in the coefficients that will balance the following reaction: a0NH4Cl + a1Ag3PO4 → a2AgCl + a3(NH4)3PO4
    7·2 answers
  • Which of these has the most covalent character? <br> NaF Caf2 Bef2 CsF SrF2
    9·1 answer
  • What is the answer to this I need help please
    11·1 answer
  • Substance A undergoes a first order reaction A  B with a half- life of 20 min at 25 °C. If the initial concentration of A ([A]◦
    6·1 answer
  • Based on the equation, determine what happens to the frequency if the period were to change from 0.2 seconds to 0.5 seconds. A)
    15·1 answer
  • Which one of the following statements BEST describes a chemical reaction?
    5·1 answer
  • A student is preparing 500 mL of a 0.1M solution of magnesium chloride to test the
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!