Answer:Protons are positively charged is the correct statement about an atom
I've also corrected the other statements
Atoms contain protons and neutrons in their nucleus
Neutrons posses no charge and are neutral
The nucleon number is the total number of protons and neutrons in a nucleus
Answer: Absolute dating is used to determine a precise age of a rock or fossil through radiometric dating methods. This uses radioactive minerals that occur in rocks and fossils almost like a geological clock. ... These isotopes break down at a constant rate over time through radioactive decay.
Answer:
330 mL of (NH₄)₂SO₄ are needed
Explanation:
First of all, we determine the reaction:
(NH₄)₂SO₄ + 2NaOH → 2NH₃ + 2H₂O + Na₂SO₄
We determine the moles of base:
(First, we convert the volume from mL to L) → 62.6 mL . 1L/1000 mL = 0.0626L
Molarity . volume (L) = 2.31 mol/L . 0.0626 L = 0.144 moles
Ratio is 2:1. Therefore we make a rule of three:
2 moles of hydroxide react with 1 mol of sulfate
Then, 0.144 moles of NaOH must react with (0.144 .1) /2 = 0.072 moles
If we want to determine the volume → Moles / Molarity
0.072 mol / 0.218 mol/L = 0.330 L
We convert from L to mL → 0.330L . 1000 mL/1L = 330 mL
Answer:
D.
Explanation:
Translation:
A. make a barbecue
B. organize a picnic
C. swimming in the pool
D. to go skiing
Barbecue is usually a summer activity, so we eliminate that.
It would be too cold for a picnic!
It would be too cold to go swimming, and that's more of a summer thing!
Skiing is a snow activity, and since it is winter, it is likely to know.
Explanation:
It is given that,
The time period of artificial satellite in a circular orbit of radius R is T. The relation between the time period and the radius is given by :
The radius of the orbit in which time period is 8T is R'. So, the relation is given by :
So, the radius of the orbit in which time period is 8T is 4R. Hence, this is the required solution.
