<span><em>Answer:</em>
A strontium-90 atom that has a lost two electrons has <u>38</u> protons, <u>52</u> neutrons, and <u>36</u> electrons.
<em>Explanation:
</em>Atomic number<em> of </em>Strontium (Sr) is 38.
<em>Atomic number = number of protons
</em>Hence, Strontium has 38 protons.
If the element is in neutral state,
number of protons = number of electrons.
Then, neutral Strontium atom should have 38 electrons.
But the question says Sr has lost 2 electrons. Hence, number of electrons should be 38 - 2 = 36.
Mass number = number of protons + number of neutrons.
The given mass number is 90. Hence, number of neutrons should be 90 - 38 = 52.</span>
An ordinary atom is balanced for instance, lithium has 3 protons and 3 electrons the positively charged proton cancels the negatively charged electron.
THINK math plus 3 and negative 3 = 0 neutral
Answer:
the Law of multiple proportions
Explanation:
The law of multiple proportions states that, if two elements A and B combine to form more than one chemical compound, then the various masses of one of the elements A, which combines with a fixed mass of the element B are in simple multiple ratio.
This is demonstrated in the formation of nitrogen compounds such as NO and N2O when nitrogen combines with oxygen. This ratio is always constant.
The distance of the earth to the sun in Mm = 1.5 x 10⁵
<h3>Further explanation</h3>
Given
The distance of the earth to the sun : 1.50 x 10⁸ km
Required
The distance in Mm
Solution
In converting units we must pay attention to the conversion factor.
the conversion factor :
1 kilometer(km) = 10⁻³ megameter(Mm)
So the distance conversion :
1.5 x 10⁸ x 10⁻³ = 1.5 x 10⁵ Mm
Answer: B
Explanation: the 3 in Na3PO4(s) belong to the sodium atom (Na). so in any of these equations, the 3 would have to be with Na.
A- the 3 is along w the PO4, which would make it part of that bond
C- there is no 3 at all for Na in this choice, making it incorrect
D- Again, the 3 is placed on the other half of the bond
