(1) Ag (3) Cu
(2) Au (4) Pb
Answer is (4) - Pb.
According to the reactivity series of elements
- the elements which are above the hydrogen are more reactive than hydrogen.
- the elements which are below the hydrogen are less reactive than hydrogen.
Among the given choices, only Pb is placed above the hydrogen in the reactivity series and rest are below the hydrogen.
Hence, Pb is more active than hydrogen.
A scientist who wants to date materials older than 40,000 years would most likely use Potassium – argon dating or K-AR dating. Potassium-40 is a radioactive isotope of potassium that decays into argon-40. The half life of potassium-40 is 1.3 billion years far longer than carbon-14.
Answer:The answer would be uranium-238 hope this helps
Explanation:
B) a polar covalent bond
C) an electronegative bond
D) a non-polar covalent bond
Answer:
A) an ionic bond
Explanation:
The mutual force of attraction between ions of opposite charges can best be described as an ionic bond.
In an ionic bond, an atom picks up electrons from the other so it becomes into a strongly electronegative atom while the other becomes into a strongly electropositive atoms and, as ions of different signs, it is generated an electrostatic attraction force between them.
b. a compass needle.
c. a circuit.
d. poles.
Answer:
d. poles
Explanation:
Magnetic field created by a solenoid:
The magnetic field created by a solenoid is increased by increasing the intensity of the current, by increasing the number of turns and by introducing a piece of iron inside the coil (electromagnet).
Solenoid coil with air core constructed with bare copper wire spirally wound and protected with insulating varnish. If we supply this coil with electric current using any source of electromotive force, such as a battery, for example, the flow of the current that will circulate through the coil will lead to the appearance of a magnetic field of a certain intensity around it.
Solenoid coil to which a metal core such as iron (Fe) has been introduced. If we compare the previous coil with air core with the coil of this illustration, we will see that now the lines of magnetic force are much more intensified as they have become an electromagnet.
chromosome
B.
chloroplast
C.
Golgi body
D.
ribosome