Answer:
The digestive system uses mechanical and chemical methods to break food down into nutrient molecules that can be absorbed into the blood. ... Some animals use intracellular digestion, where food is taken into cells by phagocytosis with digestive enzymes being secreted into the phagocytic vesicles.
Explanation:
Answer:
5. Selenium, because it does not have a stable, half-filled p subshell and adding an electron does not decrease its stability.
Explanation:
Electron affinity is the amount of energy released when an isolated gaseous atom accepts electron to form the corresponding anion.
Selenium:-
The electronic configuration of the element is:-
![[Ar]3d^{10}4s^24p^4](https://tex.z-dn.net/?f=%5BAr%5D3d%5E%7B10%7D4s%5E24p%5E4)
Arsenic:-
The electronic configuration of the element is:-
![[Ar]3d^{10}4s^24p^3](https://tex.z-dn.net/?f=%5BAr%5D3d%5E%7B10%7D4s%5E24p%5E3)
The 4p orbital in case of arsenic is half filled which makes the element having more stability as compared to selenium.
Thus, selenium has higher electron affinity because adding electron does not decrease the stability as in case of arsenic.
Potassium oxide is an ionic compound. The potassium has a charge of <span>K+</span> and oxygen has a charge of <span>O<span>2−</span></span>. We need 2 potassium ions to balance one oxide ion making the formula <span><span>K2</span>O</span>.
Potassium hydroxide is an ionic compound. The potassium has a charge of <span>K+</span> and hydroxide has a charge of <span>OH−</span>. We need 1 potassium ion to balance one hydroxide ion making the formula KOH.
<span><span>K2</span>O+<span> H2</span>O→KOH</span>
To balance the equation we place a coefficient of 2 in front of the potassium hydroxide.
<span><span>K2</span>O+<span>H2</span>O→2KOH</span>
I hope this was helpful.
Answer:
The correct options are:
1) Pure chemical substance
2) Element.
Explanation:
each of the term is explained below:
1) <u>Mixture: </u> Since tungsten is an element in periodic table thus it is not a mixture.
2) False by definition of mixture.
3) false by definition of mixture.
4) <u>Solution:</u> Tungsten in a filament is in solid form hence solution is incorrect.
5) Since it is given in the question itself that the sample is pure hence option 'E' is correct as chemical substance is a pure substance that has a homogeneous composition and the sample in the question is given as pure.
6) <u>Compound:</u> By definition of compound it is formed by mixing 2 or more elements but since tungsten is an element that occurs independently in nature hence it is not a compound.
7) Tungsten is a element in the periodic table with atomic number 74.
Answer:
8. A boat, cars, airplanes
9. It's safer to practice techniques on life sized models of human organs than practicing on an actual human. If you mess up on a model it doesn't matter, messing up on a human can put their life at risk.
