Answer:
Approximately 75%.
Explanation:
Look up the relative atomic mass of Ca on a modern periodic table:
There are one mole of Ca atoms in each mole of CaCO₃ formula unit.
- The mass of one mole of CaCO₃ is the same as the molar mass of this compound:
. - The mass of one mole of Ca atoms is (numerically) the same as the relative atomic mass of this element:
.
Calculate the mass ratio of Ca in a pure sample of CaCO₃:
.
Let the mass of the sample be 100 g. This sample of CaCO₃ contains 30% Ca by mass. In that 100 grams of this sample, there would be 
of Ca atoms. Assuming that the impurity does not contain any Ca. In other words, all these Ca atoms belong to CaCO₃. Apply the ratio 
:
.
In other words, by these assumptions, 100 grams of this sample would contain 75 grams of CaCO₃. The percentage mass of CaCO₃ in this sample would thus be equal to:
.
Explanation:
3 Earth's many natural resources, including oil, water, soil, minerals, wind, and sunlight, are unevenly distributed on Earth's surface. In other words, resources are concentrated in specific places because of the processes by which they form.
2
When plates collide or undergo subduction (that is – ride one over another), the plates tend to buckle and fold, forming mountains. Most of the major continental mountain ranges are associated with thrusting and folding or orogenesis. Examples are the Balkan Mountains, the Jura and the Zagros mountains.
1truth, there are three ways in which mountains are formed, which correspond to the types of mountains in question. These are known as volcanic, fold and block mountains
<h3>please mark me as brainlist please </h3>
Answer:
1) The value of Kc : (C.) remains the same
2) The value of Qc : (A.) is greater than Kc
3) The reaction must : (B.) run in the reverse direction to reestablish equilibrium.
4) The number of moles of Br2 will : (B.) decrease
Explanation:
Value of concentration equilibrium constant Kc depends only on temperature. Since temperature remains constant, therefore, Kc remains constant. Decrease in volume means increase in pressure. Increase in pressure favors the side with less gaseous species. Hence, increase in pressure will favor the reverse reaction towards reactants.
Answer:
I think the answer would have to be D
The answer would be C- both hydrogen and covalent bonds.
