Answer:
A. chemical substance whose atoms all have the same number of protons
Explanation:
An element is a substance which contains identical atoms that have the same number of protons in the nucleus.
Elements are arranged in the periodic table according to their atomic number (= number of protons): so atoms of different elements have a different number of protons in their nuclei.
For a neutral atom, the number of electrons around the nucleus is also equal to the number of protons.
Moreover, atoms of the same element can have a different number of neutrons, despite having the same number of protons - these atoms are called isotopes.
Answer:
Scientific Notation: 3.45 x 10^5
E Notation: 3.45e5
Answer:true
Explanation:
The lower the refractive index,the faster the velocity of light
Answer:
425 m
Explanation:
From the question,
v = 2x/t.................... Equation 1
Where v = speed of sound in air, x = Length of the lake, t = time.
make x the subject of the equation
x = vt/2............... Equation 2
Given: t = 2.5 s
Constant: v = 340 m/s.
Substitute these values into equation 2
x = 340(2.5)/2
x = 425 m.
Hence the length of the lake is 425 m
