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
blagie [28]
3 years ago
5

What two elements make up the most of the earth's core​

Chemistry
1 answer:
podryga [215]3 years ago
7 0

Answer:

The Earth's core is mainly made of iron and nickel.

Explanation:

You might be interested in
rite an equation for the formation one mole of CaCO3(s) from its elements in their standard states. Write any reference to carbo
maks197457 [2]

Answer: The chemical equation for the formation one mole of CaCO3(s) from its elements in their standard states is Ca(s)+C(s)+\frac{3}{2}O_2(g)\rightarrow CaCO_3(s)

Explanation:

The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.

The chemical equation for the formation one mole of CaCO3(s) from its elements in their standard states is:

Ca(s)+C(s)+\frac{3}{2}O_2(g)\rightarrow CaCO_3(s)

where (s) represents solid state and (g) represents gaseous state.

6 0
4 years ago
Which is the correct formula for the compound whose percent composition is shown?
miv72 [106K]
File:///Users/user/Downloads/Chemistry%20Exam%20Study%20Guide%20Fall%202012.pdf

Idk if this will help you, cuz it says what question are going to be in ur final 
6 0
3 years ago
Isotopes are atoms of a particular element that contain a different number of _____________.
sertanlavr [38]
<span>Isotopes are atoms of a particular element that contain a different number of neutrons.
An atom or element have same number of protons and electrons, but when there is a change in number of neutrons, this is called isotope of that element. There are many elements that have their isotopes like carbon have three isotopes Carbon 12, 13 and 14.</span>
3 0
3 years ago
Lt takes 4 hr 39 min for a 2.00-mg sample of radium-230 to decay to 0.25 mg. what is the half-life of radium-230?
Rufina [12.5K]
Radioactive decay => C = Co { e ^ (- kt) |

Data:

Co = 2.00 mg
C = 0.25 mg
t = 4 hr 39 min

Time conversion: 4 hr 39 min = 4.65 hr

1) Replace the data in the equation to find k

C = Co { e ^ (-kt) } => C / Co = e ^ (-kt) => -kt = ln { C / Co} => kt = ln {Co / C}

=> k = ln {Co / C} / t =  ln {2.00mg / 0.25mg} / 4.65 hr = 0.44719

2) Use C / Co  = 1/2 to find the hallf-life

C / Co = e ^ (-kt) => -kt = ln (C / Co)

=> -kt = ln (1/2) => kt = ln(2) => t = ln (2) / k

t = ln(2) / 0.44719 = 1.55 hr.

Answer: 1.55 hr
6 0
4 years ago
Many esters have characteristic odors. Methyl salicylate exhibits a pleasant wintergreen odor. This ester can be prepared from s
hodyreva [135]

Answer:

Methanol would be used as a reagent in excess, since it is a very low-cost solvent. For product isolation, the first thing to do is remove the methanol through a distillation process. The residue produced can be dissolved in diethyl ether. Using a NaHCO₃ solution, extraction is performed. When it separates into two phases, the product will be in the ether and the reagent in the aqueous phase. The ether can also be removed by distillation, and at the end of this process you will have the product you want.

Explanation:

5 0
3 years ago
Other questions:
  • How many oxygen atoms are present in 2.5 mol
    12·1 answer
  • How can human behaviors affect our natural resources?
    7·1 answer
  • 30.5 g of sodium metal reacts with a solution of excess lithium bromide. How many grams
    10·1 answer
  • Which formula is a molecular compound
    6·1 answer
  • How many mL are in 2.5 quarts?<br> (1 L = 1.05 qt)
    15·1 answer
  • What are two ways in which mixtures differ from compounds??
    13·2 answers
  • The dissociation of a weak electrolyte is suppressed when
    14·2 answers
  • True or false, The mass of an electron is equal to the mass of a neutron.
    5·1 answer
  • Definition: These are the layers of rock or soil that are distinguishable from other layers that have been
    9·1 answer
  • Which statement below describes the location of nonmetals on the periodic table?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!