Answer:
Oxygen
Explanation:
Atomic radius trend
-decreases from left to right
-increases from top to bottom
Tungsten is in period 7, which has a larger atomic radius
Oxygen is in period 2, which is in a lower energy level and is on the right side. Therefore, has a smaller atomic radius.
Answer:
12,742 km
Explanation:
Therefore, its radius is 6,371 km.
Answer:
, zirconium-103.
Explanation:
In a nuclear reaction, both the mass number and atomic number will conserve.
Let represent the unknown particle.
The mass number of a particle is the number on the upper-left corner. The atomic number of a particle is the number on its lower-left corner under the mass number. For example, for the particle , is the mass number while while is the atomic number.
Sum of mass numbers on the left-hand side of the equation:
.
Note that there are three neutrons on the right-hand side of the equation. Sum of mass numbers on the right-hand side:
.
Mass number conserves. As a result,
.
Solve this equation for :
.
Among the five choices, the only particle with a mass number of 103 is . Make sure that atomic number also conserves.
<h3>
Answer:</h3>
1.001
120.0
<h3>
Explanation:</h3>
Significant figures are used in science to determine the precision of a number. Depending on the decimal point, sig figs are counted in different ways.
Decimal Points
When counting sig figs, you always start at the first non-zero number. However, sometimes you start from the left, other times the right.
- If the decimal point is present, start counting sig figs from the left.
- If the decimal point is absent, start counting sig figs from the right.
Remember to start counting at the first non-zero number.
For people in the Americas, there is a trick to remembering this.
- If this decimal is Present, start from the Pacific. If it is Absent, start from the Atlantic.
This works because the Pacific ocean is to the left of the Americas, and the Atlantic is to the right.
4 Significant Figures
The number 1.001, has 4 significant figures. Since there is a decimal point, we start counting from the left. The first digit is not zero, so we count all four places as significant.
The number 120.0 also has 4 sig figs. Like the number above, we start counting from the left because of the decimal. The first digit on the left is not zero, so we once again count all 4 digits as significant.