Answer:
The concentration of hydrochloric acid would be estimated to be less.
Explanation:
This is because, the hydroxyl ions from water react with the hydrogen ions from the hydrochloric acid, hence decreasing the moles of hydrogen ions which lowers the acidic strength of Hydrochloric acid.
<span>D. The screw changes the direction of a force - it converts linear force into rotational force. It also reduces the force required - the closer the threads, the smaller the input force required to get the same output force.</span>
The answer is b. radon-222. The alpha decay means that it will emit an alpha particle when decays. The alpha particle has two protons and two neutrons. So Radium(88) minus two protons will become Radon(86). And the atomic mass will become 226-4=222.
Answer: Elements in Group 2
Explanation: The periodic table was arranged by Dmitri Mendeleev specifically around similarites in their chemical behaviors. He found that as atomic number increases, at some point an element starts to react in a manner similar to a previous one. When that happened, he would place the larger element under the smaller one, and eventually noticed a periodicity in the table. Elements in a column (Groups) had similiar chemical properties. We know today that these similarities are due to the electron configuration, and that these configurations repeat themselves. He left gaps in the table when he could find an existing element with properties similar to others in that group. I big leap of faith, but it worked. Elements for those missing boxes were eventually discovered.
Answer:
I remember doing this in 7th,
1. D
2. B or D, more leaning on B though
3. A
