7. What determined the temperature, density, and ratio of hydrogen to helium of the universe soon after the Big Bang? A. the rate at which the universe expanded B. the rate of nuclear fusion in the first stars C. the density of the material the universe was expanding into D. the timing of the transition from an opaque to a transparent universe

Q: 13. How should the angle of deflection of an a particle by a nucleus vary with the closeness of the…

A:

Q: 29) The basis for the carbon-14 dating method is that A) the amount of carbon-14 in all objects is…

A: This question is related to radioactive decay. Radioactive decay follows the first order kinetics.

Q: understanding

A: Dear student I have given answer to your question in the image format.

Q: Why are some atoms radioactive?

A: The radioactive nuclei are unstable and have an excess number of either protons or neutrons in the…

Q: Describe a cathode-ray tube and how it operates.

A: A cathode ray tube (CRT) is a specialized vacuum tube in which images are produced when an electron…

Q: What is the term for the elements in the series that follows element 89?

A: the term for the element in the series that follows element 89 is actinide series.

Q: A gamma ray has a frequency of 2.88 × 1 0 21 Hz. What does this mean?

A: Frequency(v) means the number of waves passing in per (means one) second of time. Unit of…

Q: -rays consist of fast-moving electrons. A) Beta B) Gamma c) Alpha D None of these E

A:

Q: CFC-114b has a tropospheric lifetime of 189 years.  Would you expect CFC-115 to have a longer or…

A: CFCs are nonflammable, non-toxic and non-carcinogenic. They consist fluorine atoms, chlorine atoms…

Q: It has been reported that the radiation dose measured in the city of Pripyat in 2010 was 6 mSv/hour…

A: Given : Radiation rate in city = 6 mSv/hour And duration given = 1 year

Q: What Is A blue flame?

A: A blue flame has to be defined below.

Q: When the Statue of Liberty was refurbished, Teflon spacers were placed between the iron skeleton and…

A:

Q: This is the heaviest naturally occurring element  A) 87Fr B) 94Pu C) 92U D) 103Lr E) 102No

A: This is the heaviest naturally occurring element-

Q: . Given 24/14 Si, a) Find the number of protons, electrons and neutrons in the neutral atom.

A:

Q: in the equation 228/90Th -------> 228/91Pa + x which particle is represented by X?

A: The term atomic number is used to describe the total number of protons which are present in the…

Q: Which of these pertains to the process by which elements are formed within stars? A. Star formation…

A: As per bartleby guidelines I answered only first question so please don't mind.Thanks in advance.

Q: The atmosphere

A: Given information: Altitude = 78.8 km

Q: There is a safe level of radioactive carbon dioxide on earth and inside your body because of:  a.…

A: As the carbon-14 founds in the upper earth atmosphere and created when neutrons originating from…

Q: Why would a scientist prefer to use the graph of radiation intensity versus (1/distance)^2 as…

A: A number of physical properties (like the force , intensity between two system) get smaller as they…

Q: Predict the boiling point for radioactive radon, Rn, given the boiling points of krypton, Kr,…

A: Boiling point of any element is directly proportional to the Atomic mass of the element. This is…

Q: What is a gamma-ray?

A: Isotopes are those elements which have same atomic number but different mass numbers. There are many…

Q: Please answer this question correctly. 1. Write the configuration of sulfur after it has achieved…

A:

Q: 2. These images were taken here on Earth. What do you think caused these formations?

A: As here action of water is present ,so I'm taking this in chemistry subject.   Images taken by…

Q: The gamma rays emitted by 60Co are used in radiation treatment of cancer. They have a frequency of…

A: Calculate the wavelength (λ)of the gamma rays emitted by 60Co. Frequency is 2.83 × 1020 s-1.…

Q: 92 UV 380 500 600 700 780 IR 7500 10. After completing the Star Spectra Activity, please explain how…

A: Answer 11)  Exoplanet atmosphere tells physical condition of the world. We can use transit…

Q: 10. In what year did Albert Einstein prove the existence of atoms Ernest Rutherford do his Gold Foil…

A: it was Albert Einstein who, starting in his epochal year of 1905, published several papers that…

Q: Among the elementary subatomic particles of physics is themuon, which decays within a few…

A: Electromagnetic spectrum involves different radiations from the lowest to the highest frequency…

Q: Convert the mass of one electron (m=9.10*10^ -31kg) to energy. Recall the speed of light c = 3.00 *…

A: Given that, m=9.10×10-31 Kg  c= 3.00×108 m s-1 Energy E = ?

Q: Why are electrons in a cathode-ray tube deflected by electric fields?

A: Given information,    The electrons in a cathode-ray tube deflected by electric fields

Q: What are the accompanying changes of: A. Iron rusting B. Burning wood C. Cooking an egg D. The…

A: There are two types of changes in the universe- physical change and chemical change.

Q: Why it is important to study nuclear chemistry in reference to engineering, especifically,…

A: Nuclear chemistry involves the study of the atomic nucleus. Now, a hundred years ago this was…

Q: The nuclear atom model proposed by Ernest Rutherfort is based on Rutherford's observation of the…

A: Concept is based on Ernest Rutherfords atomic model

Q: . O3 (g) + electromagnetic radiation ----> O2 (g) + O (g) . The form of electromagnetic radiation…

A: O3 absorbs electromagnetic radiation and decomposes to give oxygen free atom or nascent oxygen with…

Q: What happens to an electron when an atom emits energy

A: When the electron changes levels, it decreases energy and the atom emits photons. The photon is…

Q: 6Ar18  +  4He2  -->  __________  + 0?γ0   (?γ = gamma ray)

A: Nuclear reactions are those in which either one nucleus its splits to form other lighter nuclei or…

Q: Ultraviolet radiation is characterized as UVA, UVB, or UVC. Arrange these types in order of…

A:

Q: In what year was the emission of invisible rays discovered? 1896 1897 1895 1898

A: The French physicist Antoine Henri Becquerel accidentally found an uranium-rich mineral is said to…

Q: fusion began. The fusion of hydrogen atoms in the core of this proto- sun emitted large amount of…

A: Nuclear fusion takes place when two or more less stable lighter nuclei are combined under high…

Q: The range of radiation depends upon which factors?

A: The EM spectrum is generally divided into seven regions, in order of decreasing wavelength and…

Q: Which of the following is a good portable detector for identifying exposure or potential exposure to…

A: solution :       The radiation detector is used to measure different types of radiation like beta,…

Q: Use the notation from Question 3 to write symbols for a proton,a neutron, and an electron?

A: Note - Since you haven't mentioned Question 3, i will consider the general symbols of electron,…

Q: In the energy diagram below: 10-20 -1.36 x 10-19 -8.72 x -2.42 x 10-19 , Energy -5.45 x 10-19 -2.18…

A: L

Q: It takes 1.25 kJ of energy to heat a sample of pure silver from 10°C to 12.3 °C. Calculate the mass…

A: The heat capacity is the ratio of the energy supplied in the form of heat to the rise in the…

Q: 10. Why is the temperature of cosmic background radiation important to the Big Bang theory?

A: The Big Bang theory is the prevailing cosmological model explaining the existence of the observable…