Answer:
Date Significance Soviet Union Mission
August 21, 1957 First intercontinental ballistic missile (ICBM) R-7 Semyorka
October 4, 1957 First artificial satellite First signals from space Sputnik 1
November 3, 1957 First dog in orbit (Laika) Sputnik 2
January 31, 1958 First US satellite, detection of Van Allen radiation belts
Explanation:
The glass opposite to the negative electrode started to glow. Hence, option B is correct.
<h3>What is a cathode ray tube?</h3>
A cathode-ray tube (CRT) is a specialized vacuum tube in which images are produced when an electron beam strikes a phosphorescent surface.
J.J. Thomson, through his famous Cathode ray experiment, proved that all atoms contain small negatively charged particles known as electrons. In the experiment, he applied electric voltage across a cathode ray tube. a fluorescent material coating was done on the positive side. When the voltage was applied, the positive side has glowing dots.
Hence, option B is correct.
Learn more about the cathode ray tube here:
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To determine strength of attractive forces between the molecules the size of the molecules, their polarity (dipole moment), and their shape. ... If two molecules have about the same size and similar shape, the dipole-dipole intermolecular attractive force increases with increasing polarity.
Answer:
pH = 12.15
Explanation:
To determine the pH of the HCl and KOH mixture, we need to know that the reaction is a neutralization type.
HCl + KOH → H₂O + KCl
We need to determine the moles of each compound
M = mmol / V (mL) → 30 mL . 0.10 M = 3 mmoles of HCl
M = mmol / V (mL) → 40 mL . 0.10 M = 4 mmoles of KOH
The base is in excess, so the HCl will completely react and we would produce the same mmoles of KCl
HCl + KOH → H₂O + KCl
3 m 4 m -
1 m 3 m
As the KCl is a neutral salt, it does not have any effect on the pH, so the pH will be affected, by the strong base.
1 mmol of KOH has 1 mmol of OH⁻, so the [OH⁻] will be 1 mmol / Tot volume
[OH⁻] 1 mmol / 70 mL = 0.014285 M
- log [OH⁻] = 1.85 → pH = 14 - pOH → 14 - 1.85 = 12.15
Answer:
Some examples of homoatomic molecules are hydrogen gas, and oxygen gas and some examples of heteroatomic molecules are water, methane
Explanation: