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3 years ago

15. How many elements had been discovered by 1942? 92 elements or a

Chemistry

1 answer:

vesna_86 [32]3 years ago

4 0

Answer:

Explanation:

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You are examining the DNA sequences that code for the enzyme phosphofructokinase in skinks and Komodo dragons. You notice that t

jek_recluse [69]

Answer: D. Mutation in coding sequences are more likely to be deleterious to the organism than mutations in noncoding sequences.

Explanation: It was not likely to be that the coding sequences are replicated more often. The only possible explanation is that the mutations in coding is more likely to be deleterious to the organism than mutations because it is in a non coding sequence.

8 0

3 years ago

The diagram below is an artist’s impression of a single atom of element Be. The neutrons are shown with stripes, the protons are

Ahat [919]

Answer is: beryllium-10.

The diagram shows that atom has 4 protons, 5 neutrons and 2 valence electrons.

Atomic number is the number of protons, which is characteristic of a chemical element, beryllium (Be) is an element with atomic number 4.

Two valence electrons means that atom is from 2. group of periodic table, only beryllium is from that group; sodium (1. group), boron (13. group) and carbon (14. group).

Beryllium-10 has 6 neutrons, so it is isotope (different number of neutrons or mass number).

3 0

3 years ago

Read 2 more answers

What pressure will be exerted by 25 g of CO2 at temperature of 25°C and a volume of .50 L?

Grace [21]

Answer:

P = 27.9 atm

Explanation:

Given data:

Mass of CO₂ = 25 g

Temperature = 25°C (25+273.15 K = 298.15 K)

Volume of gas = 0.50 L

Pressure of gas = ?

Solution:

Firs of all we will calculate the number of moles of gas,

Number of moles = mass/molar mass

Number of moles = 25 g/ 44 g/mol

Number of moles = 0.57 mol

Pressure of gas :

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K

T = temperature in kelvin

P × 0.50 L = 0.57 mol × 0.0821 atm.L/ mol.K × 298.15 K

P = 13.95 atm.L/ 0.50 L

P = 27.9 atm

4 0

3 years ago

What do noble gases all have in common?

erastova [34]

Answer:

D. They react readily with oxygen in the air

3 0

3 years ago

Define/Differentiate between a physical property and a chemical property?

irga5000 [103]

Answer:

A physical property is an aspect of matter that can be observed or measured without changing it. A chemical property may only be observed by changing the chemical identity of a substance.

Explanation:

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4 0

4 years ago