Answer:
A
Explanation:
The answer A is the best answer because it contains the most general characteristic of a chemical change.
The sun gives off light energy to help plants photosynthesize and make food
Answer:
Aluminium.
Explanation:
The above electronic configuration can be written in a simplified form as shown below:
1s² 2s²2p⁶ 3s²3p¹
Next, we shall determine the number of electrons in the atom of the element as follow:
Number electron = 2 + 2 + 6 + 2 + 1
Number of electron = 13
Next, we shall determine the number of protons.
Since the element is in its neutral state,
The number of electrons and protons are equal i.e
Proton = Electron
Number of electron = 13
Proton = Electron = 13
Proton = 13
Next, we shall determine the atomic number of the element.
The atomic number of an element is simply the number of protons in the atom of the element i.e
Atomic number = proton number
Proton = 13
Atomic number = 13
Comparing the atomic number of the element with those in the periodic table, the element with the above electronic configuration is aluminium since no two elements have the same atomic number.
Answer:
Mass=50.0g
H=670J
change in temperature=40
using. c=h÷m×change in temperature
c=670÷50×40
C=670÷2000
C=0.335jkg-1k-1
Answer:
A telescope, printing press, and microscope
Explanation:
