The answer is an igneous rock.
Hope this helps!!
An atom of element has there subatomic particles namely, proton, electron and neutron. Here, for a neutral atom, number of proton is equal to number of electron (this is not in the case of ions), this is equal to atomic number of an atom. In an atom, nucleus contains protons and neutrons which is responsible for mass of the atom and electrons move around nucleus in fixed orbits. Thus, atomic mass of an atom is equal to sum of number of protons and neutrons.
Option (b): Proton is the particle in nucleus of an atom, whose total number is equal to atomic number of that atom.
(4) Option (b): Atoms of same element have same atomic number because mass number can be different for different isotopes of atom. Since, atomic number is equal to number of protons, thus, number of protons are same for all atoms of the same element.
(5) Option (d): Isotopes are defined as atoms of same element with same atomic number but different mass number. Thus, correct option is (d) mass numbers.
Answer:
It would be an element my dear.
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Pure gold is an element. That is, it is not a combination of other materials. However, gold used in jewelry is usually a “mixture”, called an alloy mixed with other metals to harden it, to change the color as in copper makes the pink or rose gold that is currently enjoying great polarity.
Answer:
-476.95 Kj
Explanation:
N2H4(l) + N2O4(g) = 2N2O(g) + 2H20(g)
∆Hrxn = n∆Hf(products) - m∆Hf(reactants)
Where n and m = stoichiometric coefficients of the products and reactants respectively from the balanced chemical equation, ∆Hf = standard enthalpy of formation, ∆Hrxn= standard enthalpy of reaction.
Using the following standard enthalpies of formation ( you did not provide any ):
N2H4(l) = +50.63Kj/mol; N2O4(g) = +9.08Kj/mol; N2O(g) =+33.18Kj/mol; H2O(g) = -241.8Kj/mol
∆Hrxn = [ (2(∆Hf(N2O)) + (2(∆Hf(H2O))] – [(1(∆Hf(N2H4)) + (1(∆Hf(N2O4))]
∆Hrxn = [ 2(+33.18) + 2(-241.8)] – [ (+50.63) + (+9.08)]
∆Hrxn = [ (+66.36)+(-483.6)] – [ +50.63+9.08]
∆Hrxn = [ +66.36-483.6] – [+59.71]
∆Hrxn = -417.24-59.71
∆Hrxn = -476.95 Kj
NOTE: Remember to use the standard enthalpies of formation given to you by your instructor if they differ from the values used herein, and follow the same procedure.
Answer:
It organizes all of the elements and it allows you to easily find the groups of elements such as
Group 1 of the periodic table consists of hydrogen and the alkali metals
Group 2 consists of the alkaline metals (batteries!)
Groups 3–12 contain transition metals
Groups 13–16 each contain at least one metalloid
Group 17 contains halogens
Group 18 consists of noble gases which are stable.
It is easy to read and theres a song to help you memorize them online.
Explanation:
