Answer:
Pu-239
Explanation:
Beta decay moves the element which undergoes the decay one place to the right in the periodic table since to conserve charge and being beta radiations an electron we convert a neutron into a proton and an electron. In neutron capture we increase the atomic mas by one unit. We that in mind, lets solve the question:
U-238 + ₁⁰ n ⇒ U-239 ⇒ Np -239 + ₋₁⁰β ⇒ Pu-239 + ₋₁⁰β
This assumption is not valid because, there are some elements which exist in two or more forms; they have the same atomic number but differ in their mass number, which meas that they possess different number of neutrons. These type of element are called isotopes. Isotope have the same atomic number and similar physical and chemical properties but they have different number of neutrons and therefore possess different masses.
Answer: C. HNO3 and NaOH
Explanation:
Arrhenius acid produces hydogen ion (H+) when dissolved in water. An example of Arrhenius acid is HNO3.
Arrhenius base produces hydroxyl ion (OH-) when dissolved water. An example of Arrhenius base is NaOH.
Answer:
From the graph find the maximum velocity and half it i.e. Vmax/2. Draw a horizontal line from this point till you find the point on the graph that corresponds to it and read off the substrate concentration at that point. This will give the value of Km.
Answer:
Helium is created from hydrogen in the sun's core.
Four hydrogen-1 nuclei fuse to produce
- one helium-4 nucleus, two neutrons,
- two positrons, and
- two electron neutrinos.
Explanation:
Step One:
.
Two hydrogen-1 nuclei fuse. One proton will convert to a neutron. The products will be
- one hydrogen-2 nucleus,
- one positron, and
- one electron neutrino.
Step Two:
.
There are plenty of hydrogen-1 nuclei available in the core of the sun. The hydrogen-2 nucleus from step one will fuse with a hydrogen-1 nucleus. The product is
Step Three
.
Two helium-3 nuclei from step two react with each other. The products are:
- one helium-4 nucleus, and
- two hydrogen-1 nuclei.
The overall reaction will be:
.
In other words, hydrogen nuclei in the core of the sun fuse together to form helium.
