Answer:
B. materials change their properties.
Explanation:
In a chemical change, materials often change their properties because a re-arrangement of atoms takes place.
A chemical change is one in which new kind of matter is formed.
It is always accompanied by energy changes.
- Chemical changes are not reversible.
- They lead to the production of new kinds of matter
- It involves mass changes
- Requires considerable amount of energy
Answer:
48889 years
Explanation:
Activity of the living sample Ao= 15.2 disintegration per minute
Activity of the cloth A= 8.4 disintegration per minute
Half life of 14C= 5715 years
Time taken for the decay t= the unknown
From;
0.693/5715 = 2.303/t log (15.2/8.4)
1.213 × 10^-4 = 2.303/t log (1.8095)
1.213 × 10^-4 = 0.593/t
t= 0.593/1.213 × 10^-4
t= 4888.7 years
t= 48889 years
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Below are the choice that should accompanied your question above:
<span>1) Mutation resulting in aberrant STOP codon
2) Mutation in DNA sequence
3) Mutation in splice site
4) Mutation in promoter
I think the answer should be
</span>1) Mutation resulting in aberrant STOP codon
2) Mutation in DNA sequence
Answer:
1.009 atm is the total pressure for the mixture
Explanation:
To determine the total pressure in atm, of the three gases (N₂, O₂ and Ar) we have to sum all the values.
Sum of partial pressures in a mixture = Total pressure
First of all, we need to convert the values from mmHg to atm
604.5 mmHg . 1atm / 760 mmHg = 0.795 atm
162.8 mmHg . 1atm / 760 mmHg = 0.213 atm
0.500 mmHg . 1atm / 760 mmHg = 6.58×10⁻⁴ atm
Partial pressure N₂ + Partial pressure O₂ + Partial pressure Ar = Total P
0.795 atm + 0.213 atm + 6.58×10⁻⁴ atm = 1.009 atm
Circumpolar stars
Explanation:
Stars which appears to revolve around the Polaris and do not set or go below the horizon are called circumpolar stars.
In short, this stars circles the pole.
- Circumpolar stars are not found at the equator.
- These stars do not set and they are visible at the north poles.
- The simply stay as the earth spins on its axis.
Learn more:
Stars brainly.com/question/11007330
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