Choose the best answer to the following: If two protons and two neutrons are removed from the nucleus of neon-20, a nucleus of which element remains? (a) Magnesium-22. (b) Magnesium-20. (c) Oxygen-18. (d) Oxygen-1 6.

Q: Which of the following is an acceptable atomic model for a neutral atom of carbon?

A:

Q: Where in the atom is most of its mass concentrated?

A: The atom comprises of three sub-atomic particles, proton electron and neutron. The protons and…

Q: ind the length of a side of a cube having a mass of 1.0 kg and the density of nuclear matter, taking…

A: Given,  mass, m = 1.0 kg density = 23 kg/m3 Volume, a3 length of side, a…

Q: What is given off by alpha decay?

A: When an atom experiences an alpha decay, it gives off an alpha particle made up of two protons and…

Q: How many shells are represented in the presently known periodic table?

A: In the current periodic table elements may have up to seven shells, and in each shell, there are…

Q: Choose the BEST answer to the following. When an element ejects a beta particle, the atomic number…

A: Answer:bi,e increases by 1.

Q: Which element has the lightest atoms?

A: The element that has the lightest atoms is hydrogen.

Q: certain radioactive isotope has a half-life of 4.0 hours. How much time does it take for the amount…

A: Half life = t = 4 h let the time taken in measure of no. of half lives taken to decrease be n…

Q: Given that Carbon-14 has a half-life of 5700 years, determine how long (years) it would take for it…

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Q: Two protons in an atomic nucleus repel each other, but they are also attracted to each other.…

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Q: If the size of a nucleus (in the range of 10-15 to 10-14 m) is scaled up to the tip of a sharp pin,…

A: The actual size of the nucleus is, 10-15m.The apparent size of the nucleus is, 10-5mThen, the…

Q: The atomic nucleus is most often made up of

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Q: Which of the following diagrams best represents the size of the atomic nucleus relative to the size…

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Q: -. Strontium-90 emits an alpha particle and the new nucleus formed is: O Strontium-86 O Zirconium-90…

A: Data provided: Nucleus : strontium Type of decay : alpha particle Required: The new nucleus formed…

Q: The half-life of a certain radioactive substance is 9 years. What is the yearly decor factor?

A: Given,

Q: What is the difference between atomic mass and atomic weight? Select one: a. Atomic mass is the…

A: (b) Atomic mass is the mass of an individual atom, whereas atomic weight is the average ( weighted)…

Q: Radium-226 is a common isotope on Earth, but it has a half-life of about 1600 years. Given that…

A: The decay chain of Uranium-238 gives Radium-226 which is stable isotope. The half-life of…

Q: A human skeleton found at an archeological site is found to have on 1/10 the amount of Carbon-14 one…

A: Given, N= 1/10=0.1 No= 1 T= 5730years We know that, N= No(1/2)t/T

Q: The disintegration constant of a radioactive element is 0.0023 per day. Calculate the half-life and…

A: Given: The disintegration constant is 0.0023 per day.

Q: The most common oxygen isotope is °0, but the rarer isotopes O and 10 of this element also exist in…

A:

Q: Name three different types of evidence for the existence of atoms.

A: Following are the three different type of evidence that proves the existence of the atoms.…

Q: Choose the BEST answer to the following. When an element ejects an alpha particle, the atomic number…

A: Generally nuclear decay changes the number of protons in the nucleus of an atom and changes the…

Q: Which of the following is not an element: hydrogen, carbon, oxygen, water?

A: An element is a pure substance which means it consists of only one type of atoms. When the atoms of…

Q: What is an element?

A: The matter that exists in the purest form is called an element. They cannot be changed or broken by…

Q: Carbon is one of the fundamental elements in everything that's alive on Earth. The three naturally…

A: Carbon has generally three isotopes found in nature. Isotopes are those which have the same proton…

Q: Bismuth-214 emits an alpha particle and the new nucleus formed is: O Bismuth-210 O Astatine-218…

A: Given data: Nucleus : Bismuth-214 Emits alpha particle Required: New nucleus formed

Q: What element spontaneously splits into a lighter nucleus and an even lighter helium nucleus?

A: Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller…

Q: Strontium - 90 has a half-life of 25 years.How long will it take 10 grams of Strontium - 90 to decay…

A: Given Half-life (h) = 25years Initial amount ( N0) = 10 g Final amount ( N ) = 3g

Q: What element results if you add a pair of protons gto the nucleus of mercury?

A: Number of protons n in an element of mercury is 80

Q: What do you think is the reason for an increasing atomic radius within one group?

A: As we move down a group the number of energy levels increase.

Q: A radioactive substance has a half life of 15 minutes. How much of a sample of this substancewill…

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Q: How is it possible for an element to decay “forward in the periodic table”—that is, to decay to an…

A: It is possible for an element to decay “forward in the periodic table”—that is, to decay to an…

Q: Element X has 2 isotopes. One of the isotopes has a mass of 18.9 with an abundance of 75.4%. The…

A: Given: Mass of the first isotope m1 = 18.9 with 75.4% of abundance Mass of the second isotope m2 =…

Q: The half-life of Carbon-14 is 11 years. How much of an initial 102 g sample will remain after 49…

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Q: Oxygen and hydrogen atoms combine to form water. If the nuclei in a water molecule were fused, what…

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Q: Boron has two naturally occurring isotopes, boron-10, and boron-11. Boron-10 has a mass of 10.0129…

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Q: The half-life of the radioactive element unobtanium-53 is 5 seconds. If 176 grams of unobtanium-53…

A:

Q: Choose the BEST answer to the following. When an element ejects an alpha particle, the mass number…

A: Generally nuclear decay changes the number of protons in the nucleus of an atom and changes the…

Q: What happens when Uranium-238 undergoes alpha decay and then beta decay?   Uranium-238 ->

A: Alpha decay: 92238U → 90234Th + H24e Beta decay: T90234h → P91234a + β-10

Q: You inherit 32 kg of cesium-136 after your roommate moves out and leaves it behind. Cesium-137 has a…

A: Initial mass of cesium (mo) = 32 kg half life of cesium (t1/2) = 30 years time (t) = 90 years

Q: What is the essential role of atomic number in creating new elements?

A: Atomic number is total number of electrons in atom. Most of the properties depend on valency of…

Atomic Number

Elements are the building blocks of all the matter that exist in the universe. Every element is made up of atoms that have protons, electrons, and a nucleus. In order to know the difference between the elements, an atomic number is used. Every element has its own individual atomic number. The atomic number is a single most important characteristic of an atom.