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3 years ago

Please help! 30 points! ASAP plz and correct answers only please!!

Mathematics

2 answers:

Rasek [7]3 years ago

4 0

Answer: NA and Rb and there are 20 protons in calcium!

Step-by-step explanation:

ki77a [65]3 years ago

3 0

Answer:

No. of protons = 20

No. of electrons = 20

No. of neutrons = 20

Step-by-step explanation:

Part 1 :

Na, K and Rb are in the same group.

So, K and Rb are the two elements that have the same properties as sodium ( Na ).

Part 2 :

Atomic Number of Calcium = 20

Note :

Atomic Number = No. of protons

Therefore,

No. of protons = 20

Note :

No. of neutrons = No. of protons.

Therefore,

No. of neutrons = 20

Calcium is the 20th element, with 20 protons. Since a stable atom has a net charge of 0, it must have 20 electrons.

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Figure PQRS is a rectangle.

il63 [147K]

Answer:

4th option.

Step-by-step explanation:

PQ is not congruent to QR, instead it is PQ is perpendicular to QR.

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3 years ago

A flower shop sells daffodils in bunches of 9 daffodils. The shop sells 27 daffodils. How many bunches of daffodils did the shop

amm1812

Answer:

its 3 brother

Step-by-step explanation:

you divide 27 by 9 and thats 3

6 0

3 years ago

PLEASE HELP I don’t understand<br> Please explain and answer

STatiana [176]

a) You put the scientific notation in expanded form, 671,000,000. From there just divide it by 60. 11,183,333.333 miles per minute.

b) Take the miles/minute rate and multiply it by 8.3; 92821666.6667 miles per 8.3 minutes.

Hope this helps :)

8 0

3 years ago

Write as a fraction 56:120

Fudgin [204]

56:120 = 56/120 = 7/15

7 0

3 years ago

Read 2 more answers

For each of the functions below, indicate whether the function is onto, one-to-one, neither orboth. If the function is not onto

Karo-lina-s [1.5K]

Answer:

$f_{1} :Z \rightarrow Z$ is one to one mapping, it is not onto mapping

Step-by-step explanation:

$f_{1} :Z \rightarrow Z\\ f_{1} (x) = x^{3}$

f₁(x) is one to one mapping

Let $x, y \epsilon Z$

f₁(x) = f₁(y):

x₁³ = y₁³

f₁(x) is not onto mapping

Example: If f₁(x) = 7,

x₁³ = 7

$x_{1} = \sqrt[3]{7}$

x₁ is not an element of Z

$f_{1} :Z \rightarrow Z$ is one to one mapping, it is not onto mapping

5 0

3 years ago